Trojan.W97M.COBEACON.B

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following files:

• %User Temp%\initial.dat -> encoded file
• %App Data%\Microsoft\Excel\XLSTART\addons.xla -> decoded file

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan does the following:

• Decodes %App Data%\Microsoft\Excel\XLSTART\addons.xla using the following command:
  • “certutil -f -decode “%User Temp%\initial.dat” “%App Data%\Microsoft\Excel\XLSTART\addons.xla””
• Will only proceed to its intended routine if the following conditions are true:
  • Checks for a specific User domain
  • IP address contains "{BLOCKED}.{BLOCKED}.102"

It does not exploit any vulnerability.