Threat Description

Worm:W32/Agent.T

Details

Aliases: Trojan.Downloader-1419, Trojan.Downloader.Agent.ASH, W32/Generic.m
Category: Malware
Type: WormTrojan-Downloader
Platform: W32

Summary



A type of worm that replicates by sending complete, independent copies of itself over a network.



Removal



Automatic Disinfection

Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see .

Network Disinfection

For general instructions on disinfecting a local network infection, please see Eliminating A Local Network Outbreak.



Technical Details



Worm:W32/Agent.T drops several copies of itself onto the system and downloads other additional malware from the Internet.

Execution

Upon execution, Agent.T drops the following files:

  • %windir%\yqqty.exe - A copy of itself.

It modifies the following autostart registry entry to enable its automatic execution every system boot-up:

  • [HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon] Userinit=%windir%\system32\userinit.exe,%windir%\yqqty.exe

Note: The default value is Userinit=%windir%\system32\userinit.exe

It may drop a copy of itself to several drives. The Autorun.inf file, which is a configuration file used to automatically execute the malware when a directory or drive is being opened, is also dropped together with the main executable file.

Activity

Agent.T downloads the following files from the Internet:

  • http://www.sinavip.net/A[REMOVED].asp
  • http://www.sinavip.net/L[REMOVED].txt

It then saves the files to the Windows directory using the following filenames:

  • listsas.txt
  • saslogww.txt

One of the text files contains the following download sites:

  • http://www.aame.cn/k[REMOVED].rar
  • http://www.aame.cn/c[REMOVED].rar

The downloaded files are also trojan-downloaders that are now detected as Trojan-Downloader:W32/Small.EJW and Trojan-Downloader:W32/Small.ELM.






SUBMIT A SAMPLE

Suspect a file or URL was wrongly detected? Submit a sample to our Labs for analysis

Submit Now

Give And Get Advice

Give advice. Get advice. Share the knowledge on our free discussion forum.

Learn More