Analysis by: Jaime Benigno Reyes

ALIASES:

Trojan-Dropper.Agent (Ikarus), Gen:Trojan.Heur.DP.bGW@amsAudfG (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: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware, Propagates via instant messaging applications

This worm 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 backdoor routine.

It does not drop any other file.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 17,408 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 Dec 2012
Payload: Sends messages

Arrival Details

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

Backdoor Routine

This worm does not have any backdoor routine.

Dropping Routine

This worm does not drop any other file.

Download Routine

This worm does not have any downloading capability.

Information Theft

This worm does not have any information-stealing capability.

NOTES:

This worm propagates via Skype. When an infected user uses Skype to chat with someone, this worm types and sends out the following message:

  • LOL http://www.{BLOCKED}x.uk.com/images.php?id=IMG0540250.JPG

Here is a sample screenshot:

The message contains a link that may possibly lead to malware. However, the link is now inaccessible.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.618.02
FIRST VSAPI PATTERN DATE: 26 Dec 2012
VSAPI OPR PATTERN File: 9.619.00
VSAPI OPR PATTERN Date: 27 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

Identify and terminate files detected as WORM_PESKY.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Scan your computer with your Trend Micro product to delete files detected as WORM_PESKY.A. 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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