Analysis by: Nikko Tamana
 ALIASES:

Trojan-Dropper.Agent (Ikarus), Win32/Autoit.NLS trojan (NOD32), Trojan.Agent.AXNI (Bitdefender)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This malware leverages the recent announcement of changes in Yahoo! Messenger platform.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

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.

  TECHNICAL DETAILS

File Size: 388,085 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 05 Dec 2012
Payload: Connects to URLs/IPs

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.

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • www.google.com

NOTES:

It searches if there are installed internet browsers such as Google Chrome, Mozilla Firefox and Internet Explorer. If it finds any of the following browsers, it accesses the following URLs using the browser it found:

  • http://{BLOCKED}y/2JiIW
  • http://31c3f4bd.{BLOCKED}cks.com

These are pay per click sites that enables the malware author to generate profit when users visit these sites.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.572.02
FIRST VSAPI PATTERN DATE: 05 Dec 2012
VSAPI OPR PATTERN File: 9.573.00
VSAPI OPR PATTERN Date: 06 Dec 2012

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Scan your computer with your Trend Micro product to delete files detected as TROJ_ADCLICK.TNH. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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