Tuesday, May 18, 2010

Zues, IM threats

A new threat to instant Messaging (IM) has been identified with a previously well known trojan called Zues attacking users of AOL Instant Messaging and stealing passwords.Zues is one of the best-selling Trojan kit on the black market today  and become the popular choice among cybercriminals because it’s easy to set up and control, and can be used for a variety of purposes. And, like popular commercial software, Zeus comes in a standard version (costing a minimum of $1000) and a professional version with extra features such as a large library of target templates.
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So What is Zues is?

Zues network of affected computers
Zues also known as Zbot is an threat organised by army of attackers (known as Zeus builders) who pay thousands for the latest zues builder to make sure they distribute the most up-to-date undetectable bot builds. But they are also available for free in various black market and web sites such as file sharing web sites.
Zeus/Zbot samples are distributed every day in alarming rate. It's kind of an attack  where multiple modifications of the bot are being produced in-the-wild, packed and encrypted on top with all sorts of packers, including modified, hacked, or private packer builds. Before being released, every newly generated and protected bot is uploaded into popular multi-AV scanner services to make sure it is not detected by any antivirus vendor. Hence, quite a bit of a problem in terms of its distribution scale.
latest generation Zues are capable of using the rootkit techniques to hide its presence on a customer machine.
The bot uses covert methods of injecting additional fields into online Internet banking websites, asking users to answer questions that the authentic website would not ask. The collected details are then silently delivered to remote websites, and added into remote databases. The databases are then sold to other criminal elements down the chain who specialize in withdrawing the funds. The money laundering groups anonymously hire physical people to withdraw money from their personal accounts - in the criminal world these people are called "drops", and their accounts are called "drop accounts".
Current Threat to Instant Messengers (IM)
People using the popular instant messaging platform receive an email message announcing an update and are then prompted to click through to download what appears to be a legitimate file, aimupdate_7.1.6.475.exe. However, the so-called update is actually the Zeus installer, which can then transfer itself onto the victim's machine, whether or not the AIM user clicks on the link to download the executable file.
"It opens an IFRAME to a site that attempts to use vulnerable versions of Adobe Reader to push the Zeus keylogger down to the victim's computer, then executes it within a few moments of the page loading. The fake web page to which victims are brought appears to be an AOL site, but a close look reveals inconsistencies to an authentic web page. Notably,
  • a true AIM installer has a digital signature from parent company AOL attached. This one does not contain that signature.
  • Further, the URL used for the download begins with a legitimate-seeming address, “update.aol.com”,
  • but that is followed by a six- to seven random-character word followed by .com.pl.
"The exploit opens, in an IFRAME, a page hosted on the IP address in the Vishclub network, which in turn loads a fairly large (15,628 byte) blob of obfuscated JavaScript," according to the Webroot blog post. "The script invokes the browser to load Adobe Reader, then pushes a file called 'pdf.pdf' down to the Reader. That file is built to attack the Collab overflow exploit, the util.printf overflow exploit, and the getIcon exploit in order to force the operating system to download and execute files."
Webroot Advices
Webroot advises that to avoid this particular exploit focused on AIM, users turn off Adobe Reader's embedded JavaScript. "There's almost no circumstance where JavaScript is required," Brandt said. Turning it off will give web users an extra prompt should they encounter a site that calls for Java, at which point they can make a choice.
Brandt also said that he recommends web surfers use the Firefox browser with the NoScript plug-in extension.
Known facts about Zues:
  • The ZEUS Trojan will commonly use names like below so search your PCs for files with this names:
  1. NTOS.EXE,
  2. SDRA64.exe
  3. LD08.EXE,
  4. LD12.EXE,
  5. PP06.EXE,
  6. PP08.EXE,
  7. LDnn.EXE
  8. PPnn.EXE
  • Typical size for Zues be 40KBytes and 150Kbytes .
  • Additionally look for folder with the name WSNPOEM, this is also a common sign of infection for the ZEUS Trojan.
  • Finally, check the Registry looking for RUN keys referencing any of these names.
  • Do not assume because your antivirus or internet security suite does not show any signs of infection that your PC does not have the ZEUS Trojan infection.

Sample Zues infection diagram from Trend Micro
Ways to remove Trojan manually

I found this information on Spyware techie's blog as manual removal method for techie computer users. Unknown Trojan manual removal may be difficult and time consuming to remove. There’s no guarantee that Unknown Trojan will be removed completely. So read the Unknown Trojan removal steps carefully and good luck.

Before you start: Close all programs and Internet browsers and back up your computer incase if something goes wrong.
  1. Uninstall Unknown Trojan Program
    Click on Start > Settings > Control Panel > Double-click on Add/Remove Programs. Search for and uninstall Unknown Trojan if found.
  2. To stop Unknown Trojan processes
    Go to Start > Run > type taskmgr. The click the Processes tab and you’ll see a list of running processes.
    Search and stop these Unknown Trojan processes:
    There are no processes.
    For each unwanted process, right-click on it and then select “End task”.
  3. To Unregister Unknown Trojan DLLs .To find how to delete DLL filesclick here
    Search and unregister these Unknown Trojan DLLs: There are no dll's.
    To locate the Unknown Trojan DLL path, go to Start > Search > All Files or Folders. Type Unknown Trojan and in the Look in: select either My Computer or Local Hard Drives. Click the Search button.
    Once you have the Unknown Trojan DLL path, go to Start and then click on Run. In theRun command box, type cmd, and then click on OK.
    To locate the exact DLL path, type cd in order to change the current directory. To display the contents of the directory, use the dir command. To remove the DLL file typeregsvr32 /u FILENAME.dll (FILENAME is the name of the file that you want to unregister).
  4. To unregister Unknown Trojan registry keys To know about how to remover register keys click here
    Go to Start > Run > type regedit > press OK.
    Edit the value (on the right pane) by right-clicking on it and selecting the Modify option. Select the Delete option.
    Search and delete these Unknown Trojan registry keys:
    There are no registry keys.
  5. If your homepage has been changed, go to Start > Control Panel > Internet Options> click on the General > click Use Default under Home Page. Add the your desired default homepage, then click Apply > click OK. Open a new web browser to check that you have your desired default homepage.
  6. Remove Unknown Trojan Directories.
    To find Unknown Trojan directories, go to Start > My Computer > Local Disk (C:) >Program Files > Show the contents of this folder.
    Search and delete the following Unknown Trojan directories:
    There are no directories.
    Right-click on the Unknown Trojan folder and select Delete.A message will appear saying ‘Are you sure you want to remove the folder Unknown Trojan and move all its contents to the Recycle Bin?’, click Yes.
    Another message will appear saying ‘Renaming, moving or deleting Unknown Trojan could make some programs not work. Are you sure you want to do this?’, click Yes.
  7. To remove Unknown Trojan icons on your Desktop, drag and drop them to the Recycle Bin.