W32.Qakbot

It has been reported that the following malicious Javascript may exploit certain vulnerabilities and download the threat on to the compromised computer:
[http://]b.rtbn2.cn/E/[REMOVED]

The above script exploits the following vulnerabilities:

• Microsoft Internet Explorer ADODB.Stream Object File Installation Weakness (BID 10514)
• Apple QuickTime RTSP URI Remote Buffer Overflow Vulnerability (BID 21829)

The exploit code then downloads the threat from the following location and executes it:
[http://]a.rtbn2.cn

When the threat is executed, it downloads a password-protected .zip file from following server:
[http://]a.rtbn2.cn/cgi-bin/jl/jload[REMOVED]

The .zip file contains the following updated files:

• _qbot.dll
• _qbotinj.exe

It also contains the following configuration files:

• _qbot.cb
• crontab.cb
• updates.cb

The above files are extracted to following location:
C:\Documents And Settings\All Users\_qbothome

Next, the worm creates the following registry entry so that it executes whenever Windows starts:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\"[LEGITIMATE APPLICATION NAME]" = "\"C:\Documents And Settings\All Users\_qbothome\_qbotinj.exe\" \"C:\Documents And Settings\All Users\_qbothome\_qbot.dll\" /c [PATH TO LEGITIMATE APPLICATION]"

Note: [LEGITIMATE APPLICATION NAME] is a legitimate program that already exists on the computer and is chosen randomly by the threat.

It then injects a component of itself into the iexplore.exe process.

The worm attempts to steal the following information:

• DNS, IP, hostname
• Outlook account
• Cookie
• Keystrokes
• URLs visited
• FTP server, account and password
• IRC server, account and password

It then connects to the following server to check for an Internet connection:
http://www.cdcdcdcdc2121cdsfdfd.com

Next, the worm notifies the malware author of the infection by accessing the following URL:
[http://]w1.webinspector.biz/cgi-bin/jl/jload[REMOVED]

It also contacts following the servers in order to obtain updated versions of itself, configuration files, and to send stolen information:

• [http://]a.rtbn2.cn/cgi-bin/jl/jload[REMOVED]
• [http://]c.rtbn2.cn/cgi-bin/jl/jload[REMOVED]
• [http://]adserv.co.in/u/updat[REMOVED]

The worm may receive a command from a remote attacker to enumerate network resources. If any resources are found, the worm copies itself to the shared folder.

It may also download and create following files:

• C:\Documents And Settings\All Users\_qbothome\~e5d1417.tmp
• C:\Documents And Settings\All Users\_qbothome\~e5d141a.tmp
• C:\Documents And Settings\All Users\_qbothome\~e198ac781b.tmp
• C:\Documents And Settings\All Users\_qbothome\~e439125sl.tmp
• C:\Documents And Settings\All Users\_qbothome\~efd9452.tmp
• C:\Documents And Settings\All Users\_qbothome\_installed
• C:\Documents And Settings\All Users\_qbothome\msadvapi32.dll
• C:\Documents And Settings\All Users\_qbothome\_qbotnti.exe
• C:\Documents And Settings\All Users\_qbothome\uninstall.tmp

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
• Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
• Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
• Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
• If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
• If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
• For further information on the terms used in this document, please refer to the Security Response glossary.

Summary