Thursday, May 23, 2013

Another Skype worm


Remember this post from not too long ago?
Worm spreading through Skype and Messenger

Well, seems this tactic is getting more popular...

A new Skype worm shows you the following message:

this is a very nice photo of you http://bit.ly/10UCanc?fotos=%username% :$
this is a very nice photo of you http://bit.ly/10UCanc?id=%username% :P
Other languages are possible as well, for example Russian:
это очень хорошая фотография вы http://bit.ly/10UCanc?fotos=%username%


When clicking on the link, it gets redirected to a filesharing site and downloads the following file:
facebook_profile.zip

Inside is an EXE file called:
profile-facebook_23052013_img.exe
MD5: 669441b1f5532bdc1a5371112dabc4c8
VirusTotal Result (15/46)
Anubis Result
Malwr Result

When executing the file, you start spreading this message as well to all your Skype friends. There is no icon for the EXE file, which should ring some bells... Actually, the "pictures" being a single EXE file should ring bells so hard the whole neighbourhood wakes up.


Filesharing sites used to spread the malware:
4shared.com
hotfile.com


These filesharing sites have already removed all the malicious files and cannot be downloaded anymore.
Malware files already removed, awesome!





Some interesting stats for the bit.ly link:

Current amount of clicks








Geographic distribution of clicks.





As you can see, there have been over 120,000 clicks today, that's quite a lot!  Also interesting to note is that most clicks are in Belarus, which may indicate where the malware's origin lies (or at least where the infection point started).

As far as I could see, the malware creates a file with a random name in the C:\Programdata or %appdata% folder, injects into explorer.exe and thus is able to 'protect' itself:
When deleting said malware file, it will immediately re-create.

The malware also tries to phone home to (currently offline):
hXXp://r.gigaionjumbie.biz/images/gx.php
hXXp://x.dailyradio.su/images/gx.php
hXXp://w.kei.su/images/gx.php


The above links are related with the Alureon malware, which can download other malware as well as steal your credentials and other personal information. Microsoft:
Win32/Alureon is a family of data-stealing trojans. These trojans allow an attacker to intercept incoming and outgoing Internet traffic in order to gather confidential information such as user names, passwords, and credit card data. It may also allow an attacker to transmit malicious data to the infected computer. The trojan may modify DNS settings on the host computer to enable the attacker to perform these tasks. Therefore it may be necessary to reconfigure DNS settings after the trojan is removed from the computer. Source.


There are also some peculiar strings in the malware:
lTaj13zzz5632jetsusjabs 
Regrey8hiaid958562ids  
Culmbusy4teg217jo548 
Sel35scagalawn9ser84996  
Hinog968begs6421879  
Cyme28ilkax65274sunn35  
Toph8toil2528248030  
Pent8cute812  
hoorney milk  
DESTRUCT COMMON 

Not sure what those strings are supposed to mean, if there's any meaning to it at all.
To view all strings pulled from the malware image, check Pastebin:
http://pastebin.com/Svb40p9Q



Desinfection


  • Perform a full scan with your installed antivirus ànd a scan with another antivirus or antimalware product. You can check on VirusTotal which antivirus applications already detect this worm.
  • Change your Skype password.
  • Notify your friends that you had sent them a malware link.



Conclusion

This conclusion is pretty much the same as in my previous post about a Skype worm:


Worms spreading through Facebook, Twitter as well as IRC, MSN and Skype is nothing new. Still, it appears to be very successful as human curiosity wins in cases of doubt:
"Do I really have (embarassing) pictures of myself on this website? Better take a look!"

No, no, no!

Never click on unknown links, especially when a URL shortener service like bit.ly is used. (others are for example t.co, goog.gl, tinyurl, etc.)
Don't be fooled by known icons or "legit" file descriptions, this can easily be altered.

Even if you clicked the link and you're not suspicious, you should be when a file is downloaded and no pictures are shown, but just an EXE file.

For checking what is really behind a short URL, you can use:
http://getlinkinfo.com/
http://longurl.org/

For checking whether a file is malicious or not:
https://www.virustotal.com/


Thursday, May 16, 2013

Scareware page pushing PC Speed Maximizer


Everybody should by now be aware how most scareware (aka rogueware aka fake antivirus) operates:
you receive a warning message your PC is infected with malware, and a scan needs to run immediately to help you remedy the infections.

The latest scareware is System Care Antivirus:
System Care Antivirus. (Source: BleepingComputer)





















In the past, it was just that. Scareware pushes scareware. Scareware installs scareware. Not programs that can be considered as adware or Potentially Unwanted Program (PUP/PUA).



Thanks to a headsup from Maxstar on Twitter, I was able to see how scareware was pushing "PC Speed Maximizer", which can be considered as a PUP, but not as scareware.

PC Speed Maximizer, unlike "real" scareware does not have the following behaviour:

  • Annoying pop-ups everywhere, all the time
  • Blocking internet access
  • Blocking other programs (like Task Manager for example)
  • Showing numerous errors & malware infections (where there are none)
  • No real uninstall option (because it's malware)
  • Autostarts with the PC
  • Wants to rip off users


PC Speed Maximizer however does have the following behaviour:

  • Annoying pop-ups, but not constantly
  • Showing numerous errors (where there are none)
  • Autostarts with the PC
  • Wants to rip off users



So let's get to the point here. What is the purpose of this post? To show you an apparently new tactic on how PC Speed Maximizer wants to gather money from not technically savvy users.

A new page has been set up at hxxp://pcspeedplus.com
URLVoid Result
PasteBin script


When visiting this page, you are presented with the following message:

"Critical Security Warning!" Oh really?















This pop-up or messagebox is typical for scareware, clicking the X or clicking OK has the same result...


A "scan" starts running right away:


"Virus infections have been detected!" - XP Micro Antivirus

















The following file gets downloaded:
PCSpeedMaximizer.exe
MD5:  e557bf40e5b374b2fe65cfb2502f0a99
Result: 3/46
VirusTotal Result
Anubis Result
Malwr Result
ThreatExpert Result


This file is also digitally signed:
File is digitally signed with its own cert...














Thanks to a great post here, you can find the extracted digital certificate on Pastebin:
http://pastebin.com/50cUYHEc

Surely, this is not an "APT", but it's still interesting such a piece of crap is digitally signed.



PC Speed Maximizer Setup:

Setup screen

Items to clean and optimize on your PC


Obviously there aren't that many errors on my machine, interestingly enough, it's as good as fresh out of the box. To actually be able to fix the errors you have to pay up, what a surprise.

When looking around on Google a bit, it seems others are suffering from the same scareware page and the pushing of this... software:
http://answers.microsoft.com/en-us/protect/forum/protect_other-protect_scanning/url-httppcspeedpluscomscan-keeps-bringing-up-fake/30ed02a6-2bb0-4165-84ac-56a188cfb131

This user was apparently getting fake messages when clicking on a Yahoo ad, when I received this headsup, it apparently spreads through Google Images as well.



Prevention


- Be careful when visiting any webpage. A useful trick is to check the real URL behind the image. Most of the times you can verify this by checking in the left corner of your browser:

Clicked on a picture and started loading this website instead of the original one

- Use browser extentions to verify the integrity of an image or URL. Useful add-ons for Google Chrome are for example NotScripts and WOT . For Firefox you have NoScript and WOT as well.

- Keep your Antivirus and browser, as well as your browser add-ons up-to-date.

- If it is too late and a 'scan' is already starting, immediately close your browser by bringing up Task Manager (CTRL+ALT+DEL or CTRL+SHIFT+ESC) and killing your browser's process:
  • a) For Google Chrome: chrome.exe or chrome.exe *32
  • b) For Mozilla Firefox: firefox.exe or firefox.exe *32
  • c) For Microsoft's Internet Explorer: iexplore or iexplore.exe *32




Desinfection

If the harm is already done and you are getting warnings, messages or pop-ups stating there are several errors and you need to take 'immediate action' to clean your computer, go to your
C:\Program Files\PC Speed Maximizer or C:\Program Files (x86)\PC Speed Maximizer folder and double-click on unins000.exe. The program will now uninstall itself. In that perspective, it is way less intrusive than real scareware.




Conclusion


  • Don't be fooled by warnings or message trying to scare you, it's all fake.
  • Follow the above prevention tips to decrease the chance of your computer becoming infected.


Final word: adware and/or PUP has always been annoying, and in a "grey" area for antivirus & antimalware applications to detect or not, since most of the times the EULA clearly states it's installing this software and you (as "the user") agree(s). However, pushing PUP via scareware is a new concept. I've made an earlier post about PUP and how you can prevent it as well:
http://bartblaze.blogspot.com/2013/01/about-youtube-top-comments.html

Stay safe.






Tuesday, April 2, 2013

Brazilian banking Trojan tricks


So I encountered what I suspect to be a banker focused on Brazilian banks. (Win32/Bancos)


Part 1 - spam mail:


Fiscal note

















Mail from: mail.unimedsc.com.br - 187.115.59.244 - IPvoid Result

The mail reads:
Emissão de Nota Fiscal
Prezado cliente,
Segue abaixo o(s) link(s) para acesso à nota fiscal eletrônica.
Notas Fiscais
Nota    Codigo de Verificacao    Visualizar
11932075    DTU8DBSW    NF-eletronica-8457348947..Docx
Atenciosamente,
Equipe de Cobrança:

Roughly translated:

Issue of Invoice
Dear customer,
Below is a (s) link (s) to access electronic invoices.
invoices
Note the Verification Code View
11932075 DTU8DBSW NF-electronic-8457348947 .. Docx
Sincerely,
Team Collection:

Clicking on the link leads to a ZIP file on Dropbox. I've already requested the file/URL to be removed.



Part 2 - executing the file:

The victim needs to unzip the file and run the malware:

So-called .docx with a mismatching icon





Seems the malware authors got their filetypes wrong, a .docx file should have a Word icon, not a MPEG-4 icon. ;-)
Either way, the malware is neither a Word or MPEG file, it's actually an executable, as can be seen in the screenshot above.


Some details about the file:
NF-eletronica-987812165162.Docx.exe
MD5: 65ba9ff22e4e9073dda5ecae0fd056a7
Detections: 4/46 
VirusTotal Result
Anubis Result
ThreatExpert Result

The file connects to the following IPs:
54.244.228.88 - IPvoid Result
91.136.8.9 - IPvoid Result
187.45.193.134 - IPvoid Result

This is where it gets a bit more interesting: the file downloads from 54.244.228.88 a .hlp file called:
updados.hlp - VirusTotal Result

Basically, this is a compressed .hlp file (Help-file for Windows) which contains 3 more .hlp files:
help01.hlp
help02.hlp
help03.hlp

The files then get renamed randomly and a folder in %ProgramFiles% gets created with a random filename, for example:
C:\Program Files\2x8H8g

Most malware of today gets dropped in %systemroot% or %appdata%. The following entries were added to the registry to ensure persistance:

Autorun entries with fancy icons








Part 3 - the consequenses:

  • Your (financial) data will be stolen
  • You might get a pop-up next time you log in to your bank asking for credentials
  • You might be diverted to a fake login page
  • You might finance the malware author's next vacation by unwillingly transferring X amount of money
  • Other malware might be downloaded 


Part 4 - gathered files:

Note how the .hlp files have the exact same filesize as the .exe files. (they're the same files)

Contact me for a copy.

Gathered files

























Conclusion
  • Don't click on any link(s) of unknown senders. In fact, don't even open mail from unknown senders.
  • Have you indeed ordered something? Check the status of it directly on the supplier's website.
  • Don't be fooled by the fancy icons, they are actually EXE files. You can enable an option in Windows so you're always sure of the filetype being used:
    Enable Viewing of Filename Extensions for Known File Types
  • Install an antivirus and antimalware product and keep it up-to-date & running.

Tuesday, March 12, 2013

Exploits, exploits everywhere


It's the exploit season (especially for Java).

This time, I'm seeing a lot of mails supposedly from PayPal:

Apparently you bought an expensive watch. For someone you don't know.
Looks legit.




Originating IP of this mail:
188.33.40.190 - IPvoid Result

Seems to be sent out by the Cutwail botnet.




When clicking on one of the links (they all point to the same hacked webpage):

Adobe Reader giving a warning



Firstly, a blank webpage opens up and you're getting a PDF or Java exploit which is being launched.

Adobe crashes with a warning. Should raise some suspicions.





The latest trick the malware authors perform is to ultimately redirect you to a fake pharmacy:
'Pharmacy Express'. Fake pharmacy.

You are eventually ending up on this page, probably to make you think 'it was just Viagra spam, that's all'. Wrong! In fact, you're being infected as we speak. A file gets dropped to the %appdata% folder:

xydyswylmylh.exe
Result: 6/45
MD5: 22f3c0fd2a5d9e1799699097836bb5dc
VirusTotal Result
ThreatExpert Result
Anubis Result


There were a lot of HTTP connections, possible password stealer?


Additionally, it connects to the following IPs & ports: 

Malware was downloaded from:
188.93.211.151 - IPvoid Result

Adobe/PDF exploit being used: CVE-2010-0188 - CVE Report
Oracle/Java exploit being used: CVE-2013-0431 - CVE Report (tip from @eromang)


All files gathered, contact me for a copy:
Gathered files in this attack



This spreading is still going on, if you'd like to know the source of these exploits (be careful though, they can still be live!), you can see these results from URLquery:


Conclusion


  • Don't click on any link(s) of unknown senders.
    In fact, don't even open mail from unknown senders.
  • Have you paid for an expensive watch for somebody you don't even know? I didn't think so.
  • Install an antivirus and antimalware product and keep it up-to-date & running. 
  • Use for example NoScript in Firefox to counter these attacks.
  • And above all: patch Java, Adobe and any other 3d party software you may have!





Tuesday, February 26, 2013

FedEx spam loads malware


Received an email from (supposedly) FedEx today, seems my parcel was unable to be delivered:

Print your receipt!

















    Mail details:
Subject: Shipping Information‏


Sender: stoiciu_ro01@uhost.ro


X-Originating-IP: 195.78.124.42
Content: 
FedEx
Tracking ID: 1795-21492944
Date: Monday, 18 February 2013, 10:22 AM
Dear Client,
Your parcel has arrived at February 20.Courier was unable to deliver the parcel to you at 20 February 06:33 PM.
To receive your parcel, please, print this receipt and go to the nearest office.
Print Receipt  
Best Regards, The FedEx Team.
FedEx 1995-2013


The 'Print Receipt' button points to a filesharing website, where a ZIP file gets downloaded. Inside the ZIP is an EXE file with a neat little Word icon. When running the file:


Postal Receipt  information













You get a Notepad file with some information. Is your name Mark Smith? No? Then you're infected. Is your name Mark Smith? Then you're infected anyway. 

Does this behaviour look familiar? Well noticed, we've seen this in a post from some months ago:



Gathered files. Contact me for a copy.









Some more details about the downloaded file:
Postal-Receipt.exe
MD5: d335b890e1bc260a259b994533333d02
VirusTotal Report
Anubis Report
ThreatExpert Report


The following file was dropped in the %appdata% folder:
ujfhmdlk.exe
MD5: d335b890e1bc260a259b994533333d02
VirusTotal Report
Anubis Report
ThreatExpert Report


The malware tries to connect to the following IPs:

46.105.143.110
50.115.116.201
74.117.61.123
77.79.81.166
81.93.248.152
87.106.51.52
91.121.140.40
91.121.28.146
93.125.30.232
95.140.203.241
109.235.252.2
118.97.15.13
122.155.18.53
149.62.168.76
188.165.205.46
190.111.176.13
190.111.176
202.153.132.24
213.229.106.32
217.11.63.194



It performs the following GET request on port 8080, probably to download more malware.  
(I was however unable to reproduce any additional droppers or system modifications): /509A37A363A4A88C8B6BBD234F063B9CEE4072C470F04B0AB239C05FF89DA4B98D1E54BF77C0CD96CD8BC4004B3459C13194D0F9E0D64CF108A635F7468E817F408A20EF7149233F1356D2B3565F49





Conclusion
  • Don't click on any link(s) of unknown senders. In fact, don't even open mail from unknown senders.
  • Have you indeed ordered something? Check the status of it directly on the supplier's website.
  • Don't be fooled by the Adobe or Word icons, they are actually EXE files. You can enable an option in Windows so you're always sure of the filetype being used:
    Enable Viewing of Filename Extensions for Known File Types
  • Install an antivirus and antimalware product and keep it up-to-date & running. In this case, the payload is at least 4 months old! This should be easily detected by your antivirus product.