Monday, November 23, 2020

Blue Team Puzzle

Several years ago, I created a "malware puzzle" - basically, a crossword puzzle but with terms related to malware. You can find that puzzle here: https://bartblaze.blogspot.com/2013/08/malware-puzzle.html

Seeing crosswords are a hobby of mine, I thought it'd be fun to create another one more than seven years later - this time, all things blue team! Obviously you don't need to be part of a blue team to fill in the puzzle, it's for anyone in information or cyber security - but it does help if you've been on the defense side of things.

You can print the puzzle and fill it in, or you can use Adobe Reader to complete the PDF version, or use any tool to your liking (mspaint is also a candidate). There are no spaces - all words are one word.













You can find the puzzle in the following formats:

PNG: https://www.mediafire.com/view/0iuzvxal8redjz2/crossword-iiRh073oLn.png/file

PNG mirror: https://imgur.com/a/ASATRXf

PDF: https://www.mediafire.com/file/b3v7pebohp6c8vn/crossword-xp6dZUU9Ar.pdf/file

PDF mirror: https://www.filedropper.com/crossword-xp6dzuu9ar

If you have the solution, feel free to create a comment or @ me on Twitter: https://twitter.com/bartblaze

To make things more interesting, you can set up a competition between your fellow defenders to see who can complete it first!

If you're stuck, I can always send you a hint - see my About page for contact information, use Twitter, or leave a comment. Note there may be spoilers around. 

Tuesday, January 14, 2020

Satan ransomware rebrands as 5ss5c ransomware


The cybercrime group that brought us Satan, DBGer and Lucky ransomware and perhaps Iron ransomware, has now come up with a new version or rebranding named "5ss5c".

In a previous blog post, Satan ransomware adds EternalBlue exploit, I described how the group behind Satan ransomware has been actively developing its ransomware, adding new functionalities (specifically then: EternalBlue) and techniques with each run. Then, it appeared the group halted operations on at least the ransomware front for several months.

However, as it turns out, the group has been working on new ransomware - 5ss5c - since at least November 2019.

The following tweet got my attention:


After some quick checks, it appears this is a downloader for the 5ss5c ransomware, which is extremely reminiscent of how Satan ransomware operated:

Figure 1 - 5ss5c downloader












The malware will leverage certutil and even contains logging:

Figure 2 - certutil logging









It will download and leverage:

  • Spreader (EternalBlue and hardcoded credentials);
  • Mimikatz and what appears another password dumper/stealer;
  • The actual ransomware.

The following hashes are relevant to this new variant:

Name: down.txt
URL: http://58.221.158[.]90:88/car/down.txt
Purpose: Downloader
MD5: 680d9c8bb70e38d3727753430c655699
SHA1: 5e72192360bbe436a3f4048717320409fb1a8009
SHA256: ddfd1d60ffea333a1565b0707a7adca601dafdd7ec29c61d622732117416545f
Compilation timestamp: 2020-01-11 19:04:24
VirusTotal report:
ddfd1d60ffea333a1565b0707a7adca601dafdd7ec29c61d622732117416545f

down.txt is, as mentioned, the downloader for the spreader module and for the actual ransomware:

Name: c.dat
URL: http://58.221.158[.]90:88/car/c.dat
Purpose: spreader
MD5: 01a9b1f9a9db526a54a64e39a605dd30
SHA1: a436e3f5a9ee5e88671823b43fa77ed871c1475b
SHA256: 9a1365c42f4aca3e9c1c5dcf38b967b73ab56e4af0b4a4380af7e2bf185478bc
Compilation timestamp: 2020-01-11 19:19:54
VirusTotal report:
9a1365c42f4aca3e9c1c5dcf38b967b73ab56e4af0b4a4380af7e2bf185478bc

Name: cpt.dat
URL: http://58.221.158[.]90:88/car/cpt.dat
Purpose: ransomware
MD5: 853358339279b590fb1c40c3dc0cdb72
SHA1: 84825801eac21a8d6eb060ddd8a0cd902dcead25
SHA256: ca154fa6ff0d1ebc786b4ea89cefae022e05497d095c2391331f24113aa31e3c
Compilation timestamp: 2020-01-11 19:54:25
VirusTotal report:
ca154fa6ff0d1ebc786b4ea89cefae022e05497d095c2391331f24113aa31e3c
Fun fact: file version information contains "TODO: 5SS5C Encoder".

The compilation times are sequential, which makes sense - the downloader has been developed (and compiled) first, then the spreader and the actual ransomware.

Note that cpt.exe as filename has already been observed in Satan ransomware.

Further indicators, such as hashes, URLs, file paths and so on will be posted at the end of this blog post.


5ss5c - still in development - and with oddities

There's quite some curiosities that indicate 5ss5c is still in active development and stems from Satan ransomware, for example:

  • There are several logs created, e.g. there is a file "C:\Program Files\Common Files\System\Scanlog" that simply logs whether IPC SMB is open/available;
  • Certutil logging (successful download or not);
  • There are several Satan ransomware artefacts;
  • Other Tactics, Techniques and Procedures (TTP) align with both Satan (and DBGer), and slightly overlap with Iron: 
    • One of these is, for example, the use of multiple packers to protect their droppers and payloads. 
    • This time however, they decided to use both MPRESS and Enigma, and even Enigma VirtualBox! (Note: Enigma and Enigma VirtualBox are not the same - the latter is a virtualised packer and also referred to as EnigmaVM.)


However, there are quite some curiosities, one of them being what appear to be hardcoded credentials:

Figure 3 - Hardcoded creds




















These hardcoded credentials will be leveraged in an attempt to connect to an SQL database with the xp_cmdshell command:

Curiously, we can identify the following data inside the ransomware in regards to the SQL database:
  • ecology.url
  • ecology.password
  • ecology.user
Searching a bit further, we can discover a company named Finereport (https://www.finereport.com/en/company), which claims to be "Top 1 in China’s BI market share in IDC "China BI Software Tracker, 2018". You guessed it - it uses SQL as database.

What else is new is, as mentioned before, the use of Enigma VirtualBox for packing an additional spreader module, aptly named poc.exe. This suggest they may be experimenting (poc often is an acronym for proof of concept).

This file will be dropped to C:\ProgramData\poc.exe and will run the following command:

cd /D C:\ProgramData&star.exe --OutConfig a --TargetPort 445 --Protocol SMB --Architecture x64 --Function RunDLL --DllPayload C:\ProgramData\down64.dll --TargetIp 
Now compare this to Satan ransomware's 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 
Something looks similar here... :-)


5ss5c ransomware - how it operates

Back to the actual ransomware. It will create the following mutexes:
  • SSSS_Scan (in previous iterations SSS_Scan has also been observed)
  • 5ss5c_CRYPT

Just like its predecessor, 5ss5c also has an exclusion list, where it will not encrypt specific files as well as files in the following folders:

Figure 4 - Exclusion list

















For example, the following folders belonging to Qihoo 360 (an internet security company based in China also offering antivirus) were already excluded in Satan and DBGer ransomware:

  • 360rec
  • 360sec
  • 360sand


While these are new in 5ss5c ransomware:

  • 360downloads
  • 360safe


As in previous iterations, 5ss5c ransomware will stop database-related services and processes.

It will however only encrypt files with the following extensions:
7z, bak, cer, csv, db, dbf, dmp, docx, eps, ldf, mdb, mdf, myd, myi, ora, pdf, pem, pfx, ppt, pptx, psd, rar, rtf, sql, tar, txt, vdi, vmdk, vmx, xls, xlsx, zip
This extension list is not like before, and includes mostly documents, archives, database files and VMware-related extensions such as vmdk.

The ransomware will then create the following URI structure to communicate with the C2 server (61.186.243[.]2):

  • /api/data.php?code=
  • &file=
  • &size=
  • &status=
  • &keyhash=
It will also create a ransomware note on the C:\ drive as: _如何解密我的文件_.txt which translates to _How to decrypt my file_.txt. Example content is as follows:

Figure 5 - ransom note














The content reads:


部分文件已经被加密
如果你想找回加密文件,发送 (1) 个比特币到我的钱包
从加密开始48小时之内没有完成支付,解密的金额会发生翻倍.
如果有其他问题,可以通过邮件联系我

您的解密凭证是 :

Email:[5ss5c@mail.ru]

Translated:

Some files have been encrypted
If you want to retrieve the encrypted file, send (1) Bitcoins to my wallet
If payment is not completed within 48 hours from the start of encryption, the amount of decryption will double.
If you have other questions, you can contact me by email
Your decryption credentials are:

Email: [5ss5c@mail.ru]

Interestingly, the ransomware note does not contain a Bitcoin address. Additionally, the note only contains instructions in Chinese, not Korean nor English like previous iterations. Is 5ss5c ransomware more targeted, or just actively being tested by the group/developers behind it?

Encrypted files will have the actor's email address prepended and a unique token with the ransomware's name will be appended, for example;
test.txt becomes [5ss5c@mail.ru]test.txt.Y54GUHKIG1T2ZLN76II9F3BBQV7MK4UOGSQUND7U.5ss5c.


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;
  • Install a firewall, or enable the Windows Firewall;
  • Restrict, where possible, access to shares (ACLs);
  • Create backups! (and test them)
More ransomware prevention can be found here.

Conclusion

Satan is dead, long live 5ss5c! It just doesn't sound as good, does it?

Whoever's behind the development of Satan, DBGer, Lucky and likely Iron ransomware, is back in business with the 5ss5c ransomware, and it appears to be in active development - and is trying to increase (or perhaps focus?) its targeting and spread of the ransomware.

It is recommended organisations detect and/or search for the indicators of compromise (IOCs) below, and have proper prevention controls in place. MITRE ATT&CK IDs can also be found below.

Indicators of Compromise:



Type Indicator
File C:\Program Files\Common Files\System\Scanlog
File C:\Program Files\Common Files\System\cpt.exe
File C:\Program Files\Common Files\System\tmp
File C:\ProgramData\5ss5c_token
File C:\ProgramData\blue.exe
File C:\ProgramData\blue.fb
File C:\ProgramData\blue.xml
File C:\ProgramData\down64.dll
File C:\ProgramData\mmkt.exe
File C:\ProgramData\poc.exe
File C:\ProgramData\star.exe
File C:\ProgramData\star.fb
File C:\ProgramData\star.xml
Registry key SOFTWARE\Microsoft\Windows\CurrentVersion\Run\5ss5cStart
Command C:\Windows\system32\cmd.exe /c cd /D C:\ProgramData&blue.exe --TargetIp
Command star.exe --OutConfig a --TargetPort 445 --Protocol SMB --Architecture x64 --Function RunDLL --DllPayload C:\ProgramData\down64.dll --TargetIp
Mutex SSSS_Scan
Mutex 5ss5c_CRYPT
Email 5ss5c@mail.ru
URL http://58.221.158.90:88/car/down.txt
URL http://58.221.158.90:88/car/c.dat
URL http://58.221.158.90:88/car/cpt.dat
IP 58.221.158.90
IP 61.186.243.2
Hash 82ed3f4eb05b76691b408512767198274e6e308e8d5230ada90611ca18af046d
Hash dc3103fb21f674386b01e1122bb910a09f2226b1331dd549cbc346d8e70d02df
Hash 9a1365c42f4aca3e9c1c5dcf38b967b73ab56e4af0b4a4380af7e2bf185478bc
Hash af041f6ac90b07927696bc61e08a31a210e265a997a62cf732f7d3f5c102f1da
Hash ca154fa6ff0d1ebc786b4ea89cefae022e05497d095c2391331f24113aa31e3c
Hash e685aafc201f851a47bc926dd39fb12f4bc920f310200869ce0716c41ad92198
Hash e5bb194413170d111685da51b58d2fd60483fc7bebc70b1c6cb909ef6c6dd4a9
Hash ddfd1d60ffea333a1565b0707a7adca601dafdd7ec29c61d622732117416545f
Hash ef90dcc647e50c2378122f92fba4261f6eaa24b029cfa444289198fb0203e067
Hash 47fa9c298b904d66a5eb92c67dee602198259d366ef4f078a8365beefb9fdc95
Hash 68e644aac112fe3bbf4e87858f58c75426fd5fda93f194482af1721bc47f1cd7
Hash ea7caa08e115dbb438e29da46b47f54c62c29697617bae44464a9b63d9bddf18
Hash 23205bf9c36bbd56189e3f430c25db2a27eb089906b173601cd42c66a25829a7
Hash a46481cdb4a9fc1dbdcccc49c3deadbf18c7b9f274a0eb5fdf73766a03f19a7f
Hash cf33a92a05ba3c807447a5f6b7e45577ed53174699241da360876d4f4a2eb2de
Hash 8e348105cde49cad8bfbe0acca0da67990289e108799c88805023888ead74300
Hash ad3c0b153d5b5ba4627daa89cd2adbb18ee5831cb67feeb7394c51ebc1660f41
Hash de3c5fc97aecb93890b5432b389e047f460b271963fe965a3f26cb1b978f0eac
Hash bd291522025110f58a4493fad0395baec913bd46b1d3fa98f1f309ce3d02f179
Hash 75d543aaf9583b78de645f13e0efd8f826ff7bcf17ea680ca97a3cf9d552fc1f
Hash 50e771386ae200b46a26947665fc72a2a330add348a3c75529f6883df48c2e39
Hash 0aa4b54e9671cb83433550f1d7950d3453ba8b52d8546c9f3faf115fa9baad7e
Hash 5d12b1fc6627b0a0df0680d6556e782b8ae9270135457a81fe4edbbccc0f3552


These indicators are also available on AlienVault OTX:
Satan ransomware rebrands as 5ss5c ransomware

MITRE ATT&CK techniques



Tuesday, November 19, 2019

Monero download site and binaries compromised


Introduction

Earlier this evening I saw a tweet appear which claimed Monero has been hacked and a malicious binary (instead of the real one) has been served:


Post on Reddit:
https://www.reddit.com/r/Monero/comments/dyfozs/security_warning_cli_binaries_available_on/

Github issue:
https://github.com/monero-project/monero/issues/6151


Linux binary

Thanks to user nikitasius I was able to retrieve the malicious binary:
https://github.com/monero-project/monero/issues/6151#issuecomment-555511805

This binary is an ELF file with the following properties:
When comparing the legitimate file and this ELF file, we notice the file size is different, and a few new functions have been added:

cryptonote::simple_wallet::send_seed

This function is immediately called after either opening or creating a new wallet, as can be seen in Figure 1 and 2 below.


Figure 1 - Create wallet (legitimate)

Figure 2 - Call new seed function






















The seed will be sent to: node.hashmonero[.]com.

cryptonote::simple_wallet::send_to_cc

As you may have guessed, this function will send data off to the CC or C2 (command and control) server - this will be stolen funds.

Figure 3 - Send to cc







Sending funds to the C2 is handled using an HTTP POST request to the following C2 servers:

  • node.xmrsupport[.]co
  • 45.9.148[.]65

As far I can see, it doesn't seem to create any additional files or folders - it simply steals your seed and attempts to exfiltrate funds from your wallet.

Windows binary

The C2 server 45.9.148[.]65 also hosts a Windows binary with the following properties:


The Windows version is essentially doing the same things as the Linux version - stealing your seed and wallet funds - the function names are just different, e.g. _ZN10cryptonote13simple_wallet9send_seedERKN4epee15wipeable_stringE.

Figure 4 - Send to cc








Note: this doesn’t mean the official Windows binary was also compromised - it simply means there’s also a compromised Windows binary out there. Only the Monero team can confirm if other binaries (besides the Linux one mentioned in this blog) have been compromised.

Detection

Note: What is a hash? A hash is a unique identifier. This can be for a file, a word, ... It is preferred to use SHA256 hashes for file integration checks, as it is more secure.

You may also use the following Yara rule to detect the malicious or compromised binaries:
Monero_Compromise.yar
Download Yara (and documentation) from:
https://github.com/VirusTotal/yara

There's an additional analysis by SerHack here:
https://serhack.me/articles/cli-binaries-compromised-monero-analysis/

Recommendations
Note: Especially go through the steps if at any point you downloaded, used or installed new binaries between these dates: Monday 18th 1:30 AM UTC and 5:30 PM UTC. Download the latest version from: https://web.getmonero.org/downloads/.

Monero team statement

The Monero team has issued a statement as follows:

Warning: The binaries of the CLI wallet were compromised for a short time:
https://web.getmonero.org/2019/11/19/warning-compromised-binaries.html

I expect this statement to be updated the following days, so monitor it as well.


Conclusion

Monero is not the first, nor will it likely be the last cryptocurrency (in this case, its website and binaries) that gets compromised.

Follow the steps in this blog post to protect yourself and always watch your online accounts closely, especially those where you have financially invested in. Use strong passwords, use MFA (or 2FA) where possible and always be vigilant. Verify hashes when a new version is available.

Note: this blog post is not intended to be a full analysis, but rather a quick report on the facts, including recommendations. Questions or feedback? Happy to hear it!

Let me know in the comments below or on Twitter.



Indicators


Indicator typeIndicator
FileHash-SHA2567ab9afbc5f9a1df687558d570192fbfe9e085712657d2cfa5524f2c8caccca31
FileHash-SHA256963c1dfc86ff0e40cee176986ef9f2ce24fda53936c16f226c7387e1a3d67f74
hostnamewww.hashmonero.com
hostnamenode.xmrsupport.co
hostnamenode.hashmonero.com
FileHash-MD5d267be7efc3f2c4dde8e90b9b489ed2a
FileHash-MD572417ab40b8ed359a37b72ac8d399bd7
FileHash-SHA16bd94803b3487ae1997238614c6c81a0f18bcbb0
FileHash-SHA1394bde8bb86d75eaeee69e00d96d8daf70df4b0a
IPv491.210.104.245
IPv445.9.148.65
domainhashmonero.com
domainxmrsupport.co

On AlienVault:

https://otx.alienvault.com/pulse/5dd4574fc7c82cddbdcb8d12

MITRE ATT&CK techniques

ID: T1195 - Supply Chain Compromise
ID: T1199 - Trusted Relationship

Sunday, March 17, 2019

Run applications and scripts using Acer's RunCmd


This weekend I was cleaning up an old Acer laptop of mine and discovered a hidden folder on the root drive, C:\OEM.

Inside's a bunch of interesting files, one of these is a tool called RunCmd_X64.exe.

The file is a legitimate and signed binary by Acer:

Figure 1 - Signed RunCmd_X64




















The tool contains a useful help file as follows:

A tool to execute a command file.
RunCmd.exe filepath [/T | /F]
filepath full path name or file name
/T launch command file and open the console window
/F launch command file and hide the console window
If there is not any flag, /T or /F, the default situation is hiding window
Examples:
RunCmd.exe "D:\EnBT.cmd" /T
RunCmd.exe "EnBT.cmd" /F

Simply put, you can use Acer's tool as an alternative to the built-in command prompt, and to launch other applications! Additionally, using the /F parameter or flag will hide the console window, which is by default if there isn't any parameter!

Some simple examples:

Run an application directly

Figure 2 - Running calc.exe














Run virtually anything using a script 

Figure 3 - Running calc using a batch file










Note that since no parameter is used, the RunCmd tool will run silently and tools such as Process Explorer show a non-existent parent process.

In theory, you can run any script or scriptlet using Acer's tool to execute "command files" :)

For attackers

This "LOLBin", or at the least reusing a legitimate and signed binary for malicious purposes, has the following MD5 hash:

RunCmd_X64 - d71fb1b03bf84fae29af9b2dc525ba33

There is also a 32-bit version, however, this binary is not signed.

RunCmd - 4d50588568cae95331f00cbdb52be37a


For defenders

See "For attackers". Additionally, the RunCmd tool will attempt to create a folder named "RunCmdLog" to store logfiles. An example logfile is as follows:

2019-03-17 21:00:37 [  193C] TRACE main - ENTER: main
2019-03-17 21:00:37 [  193C] TRACE main - EXIT: main
2019-03-17 21:00:37 [  193C] INFO main - Para 1: calc.bat
2019-03-17 21:00:37 [  193C] INFO main - Para 2:
2019-03-17 21:00:37 [  193C] INFO main - command: C:\Tools\Acer\calc.bat
2019-03-17 21:00:37 [  193C] INFO main - command success
Log files will have the following format:
%s%02d-%02d-%02d %02d-%02d-%02d.log

Where %s is RunCmd and %02d is the date and time of execution. In our example above:
RunCmd2019-03-17 21-00-37.log

Why try using LOLBins when you can use tools installed by the manufacturer?


Resources

Github - Living Off The Land Binaries and Scripts (and also Libraries)
Hexacorn - Reusigned Binaries – Living off the signed land


Monday, March 4, 2019

Analysing a massive Office 365 phishing campaign


Last week, a friend of mine reached out with a query: a contact in his address book had sent him a suspicious email. As it turns out, it was. In this blog post, we'll have a quick look at an Office 365 phishing campaign, which turned out to be massive. This type of phishing has been on the rise for a while now (at least since 2017), and it's important to point out, as seemingly attacks are only increasing.


Analysis

As mentioned earlier, Office 365 (O365) phishing isn't new, but it is definitely prevalent. A high-level overview of a typical attack is as follows:

Figure 1 - High-level overview of typical O365 phishing
















A typical flow of such an attack may be as follows:


  1. An attacker sends an O365 spearphishing email, likely from a spoofed or fake email address;
  2. The user is enticed to click on the link, or open the attachment which includes a link;
  3. The user will then unknowingly enter their credentials on the fake O365 page;
  4. Credentials get sent back to the attacker;
  5. Attacker will access the now compromised user's mailbox; and,
  6. The cycle repeats: the attacker will send spearphish emails to all of the compromised user's contacts - with this difference, it's coming from a legitimate sender.
This is exactly what happened to a friend of mine: he got sent an email from a legitimate email address, which was a contact in his address book - only the sender never intentionally sent this email! 

Let's have a look at the infection chain.

The initial email

The initial email sent looked as follows:

Figure 2 - "P.AYMENT COPY"












Clicking on the "OPEN" button would redirect you to a legitimate but compromised Sharepoint (part of O365) webpage. Seeing as a legitimate business has been compromised, I won't post the link here. Its web administrators have been notified.


Figure 3 - "Access OneDrive"













The PDF document

Next step is hosting a PDF named "INVOICE.PDF", which entices the user to access OneDrive to view the shared file. If the user were to click on "OPEN PDF HERE":


Figure 4 - "Login with Office 365"















URI: https://happymachineit[.]info/Michael/b4fb042ba2b3b35053943467ac22a370/OFE1.htm

The final landing or phishing page


Finally, clicking on "Login with Office 365" will redirect the user to the final phishing page, which will look as follows:

Figure 5 - Final landing page
















The final landing page is as follows:
https://happymachineit[.]info/Michael/b4fb042ba2b3b35053943467ac22a370/7hsfabvj2b0b9rguzbzw910d.php

When entering credentials, they will be sent off to the attacker, and the cycle from Figure 1 will repeat itself. Note that other scenarios are possible, for example:
  1. The attacker may try to (re-)sell credentials that have been gathered so far on criminal forums
  2. The attacker may send more targeted spearphishes to potentially interesting victims
  3. The attacker may attempt to access other services or accounts using the same user/password combination
In short, there's countless other possibilities.

The phishing infrastructure

Avid readers will have noticed the phishing website uses a valid SSL certificate, which has the following details:


  • Subject DN: CN=happymachineit.info
  • Issuer DN: C=US, ST=TX, L=Houston, O=cPanel, Inc., CN=cPanel, Inc. Certification Authority
  • Serial: 169382499542171049850152621295591104087
The SSL cert was issued by Comodo in January. Details can be found on Censys.io.

An additional email address is connected with "happymachine": fudtoolshop@gmail.com

The phishing website encountered here, https://happymachineit[.]info, is hosted on the following IP: 178.159.36[.]107

Pivoting on that IP brings us to the following SSL certificate details:

emailAddress=ssl@server.localhost.com, CN=server.localhost.com

This means the certificate is a local and self-signed one. In other words, if you are accessing a secure website, and you see "server.localhost.com" as the SSL certificate, do NOT trust it. This is sometimes from an automatic setup from the hosting provider.

As a side-note, a search for the Common Name (CN) mentioned above with Censys currently yields 473 (unexpired certs) results: https://censys.io/certificates?q=%28server.localhost.com%29+AND+tags.raw%3A+%22unexpired%22&

Performing a search with RiskIQ's PassiveTotal as well as VirusTotal, and after filtering results, we obtain a whopping total of 875 unique Office 365 phishing sites, hosted on that IP alone! It appears this campaign has been active since December 2018.

Searching a bit further, it appears the whole ASN (which is a collection of IP prefixes controlled by a single entity, typically an ISP), AS48666 is in fact riddled with Office 365 as well as other phishing sites. Using URLscan.io we can quickly gauge the ASN is hosting multiple phishing sites for Office 365 as well as Adobe:

Figure 6 - AS48666 hosting badness










General Info:

  • Geo: Russian Federation (RU) — 
  • AS: AS48666 - AS-MAROSNET Moscow, Russia, RU 
  • Registrar: RIPENCC

As shown in this blog post, one IP address can host tons of phishing instances, while the ASN controls multiple IPs. Bonus bad IP: 178.159.36[.]120. 


Detection

For the phishing websites itself, any network traffic that resolves to the IP above.

I've noticed there are countless similar PDFs from this same campaign. Due to the way these are created (likely in bulk), a simple Yara rule can be developed as follows:











The Yara rule can be found on Pastebin here or on Github Gist here.

Note: in specific instances, this rule may false-positive - so use at your own will.

The following MITRE ATT&CK techniques are relevant:



Disinfection

There isn't much to disinfect, since there's no actual malware involved.

However, if you have been affected by this phishing campaign, do the following immediately:

  • Contact your network and/or system administrator or managed services provider if you have one and wait for their response - if not;
  • Note down the phishing page/URL, then close any open phishing pages - in fact, close the whole browser;
  • Perform an antivirus scan with your installed product, and a scan with another application, for example Malwarebytes (better be safe than sorry);
  • Change your O365 password immediately;
  • Change passwords on other websites where you used the same combination;
  • Reach out to the people in your address book you were compromised and they are not to open your email(s) or at least not any attachments or links from your email(s);
  • Verify your "Sent" emails folder (or "Outbox") for any suspicious activity. If there are no Sent emails - the attacker may have deleted them, or you may have a full compromise on your hands.;
  • Verify any (newly) created rules in your mail application (in this case O365), for example, verify there are no new forwarding rules or perhaps rules that delete new incoming emails - forwarding rules and deletion rules are sometimes set up by an attacker to gather more information or as an attempt to remain hidden; and,
  • File a complaint with your CERT, local police station, or whichever authority would handle such cases. If you are unsure how to do so, have a look here for assistance.


Prevention

  • Block the IP (or whole subnet 178.159.36[.]0/24) mentioned in this report in your firewall or proxy or other appliance;
  • Use strong and preferably unique passwords (use a password manager);
  • Set up 2FA for accounts or, preferably, MFA (multi-factor authentication);
  • Enable, deploy or implement anti-spam and anti-phishing protection;
  • Enable, deploy, or implement a URL phishing filter;
  • Trust, but verify: "did this contact really need to send me a "Payment Copy"? - if needed, verify via a phone call - not via email;
  • Be generally cautious with links and attachments. Do not click on links or open attachments from unknown senders;
  • If possible, use Firefox with NoScript enabled; and,
  • If you're in an organisation: create or organise user awareness training.

Conclusion

Phishing has been around for a long time - Office 365 phishing, on the other hand, has been around since, well, Office 365 was created. Every time a new service is created, you can imagine that phishing emails targeting that service will follow - maybe one month later, perhaps a year later - but they will.

Always try to be vigilant and follow the prevention tips mentioned above to stay safe.

As a side-note, the real Office 365 page is: https://outlook.office365.com/owa

You may find more information in the Resources section below.

Resources

Blaze's Security Blog - Cybercrime Report Template
Decent Security - Easily Report Phishing and Malware
Microsoft - Anti-phishing protection in Office 365
Microsoft - Microsoft publishes guidance to boost public sector cloud security
Microsoft - Set up multi-factor authentication
Microsoft - Set up Office 365 ATP anti-phishing and anti-phishing policies

Indicators