JS_NEMUCOD.ELDSAUFR

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

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 component file(s):

• %User Temp%\6322.DOC

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

Download Routine

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

• http://{BLOCKED}ra.net/crmain.cd
• http://www.{BLOCKED}imum.biz/nvidi.oct

It saves the files it downloads using the following names:

• %User Temp%\tmp702677.446

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

Trend Micro detects the dowloaded file as:

• TSPY_URSNIF.WMZ
  NOTE: The downloaded file may change depending on the server. As of this writing, this is the detection of the downloaded file.

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

Other Details

This Trojan does the following:

• It executes the following command for its routine:
  "%System%\cmd.exe" /c echo aassyuKEasa & cmd /c echo 98i3yusdsdfd & cmd /c echo eval(/*11613*/unescape(WScript.Arguments(0))) > %User Temp%\6322.DOC & timeout 5 & wscript /e:jscript %User Temp%\6322.DOC {JavaScript code}

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

NOTES:

This malware arrives as an embedded file on a Word Document file. It will execute its routine upon activation by the user: