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Added to the Dr.Web virus database: 2012-02-03

Virus description added:

A backdoor that replicates itself to %Temp%\rundll_.exe and registers itself with the rundll_ name in the following registry branch:

Then the malware checks the presence of its copy via a mutex.

In a temporary folder, the backdoor creates several additional files that it uses while operating:

  • rundll_.nolog—if this file is missing after the Trojan is launched, the malware creates it; the file is used to determine whether the malicious program needs to log events or not;
  • rundll_.log—the Trojan logs events into this file if rundll_.nolog is missing after the malware is launched;
  • rundll_.exe—the file to which the Trojan replicates itself;
  • rundll_.bat—the executable file created automatically to copy the Trojan to rundll_.exe;
  • rundll_twain64.dll—a REG file containing commands to save data to the system registry branch responsible for autorun;
  • rundll_dll.sid—the file is used to store the computer's unique identifier (SID); SID looks as follows: nnn550.rrr, where nnn indicates the decimal representation of the volume serial number, the 550 number is hard-coded in the Trojan's body, and rrr indicates 16 random lowercase Latin characters from the a–w range (22 characters);
  • rundll_dll.dll—the file with the command and control server address.

The Trojan can execute the following commands:

  • SERVADDR—set a new command and control server address
  • GETKILL—kill its own process
  • USE_TEMP—set a new working folder
  • USE_AP
  • GETRESTART—restart
  • SCREEN—take a screenshot and send it

Curing recommendations

  1. If the operating system (OS) can be loaded (either normally or in safe mode), download Dr.Web Security Space and run a full scan of your computer and removable media you use. More about Dr.Web Security Space.
  2. If you cannot boot the OS, change the BIOS settings to boot your system from a CD or USB drive. Download the image of the emergency system repair disk Dr.Web® LiveDisk , mount it on a USB drive or burn it to a CD/DVD. After booting up with this media, run a full scan and cure all the detected threats.
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Use Dr.Web Anti-virus for macOS to run a full scan of your Mac.

After booting up, run a full scan of all disk partitions with Dr.Web Anti-virus for Linux.

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Download by serial number

  1. If the mobile device is operating normally, download and install Dr.Web for Android. Run a full system scan and follow recommendations to neutralize the detected threats.
  2. If the mobile device has been locked by Android.Locker ransomware (the message on the screen tells you that you have broken some law or demands a set ransom amount; or you will see some other announcement that prevents you from using the handheld normally), do the following:
    • Load your smartphone or tablet in the safe mode (depending on the operating system version and specifications of the particular mobile device involved, this procedure can be performed in various ways; seek clarification from the user guide that was shipped with the device, or contact its manufacturer);
    • Once you have activated safe mode, install the Dr.Web for Android onto the infected handheld and run a full scan of the system; follow the steps recommended for neutralizing the threats that have been detected;
    • Switch off your device and turn it on as normal.

Find out more about Dr.Web for Android

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