Analysis by: Christopher Daniel So

ALIASES:

Backdoor:Win32/Mecklow.A (Microsoft), Generic BackDoor!cvd (McAfee), Trojan-Downloader.Win32.Small.bkzp (Kaspersky)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 36,864 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 19 Jan 2011

Arrival Details

This backdoor 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 backdoor connects to the following websites to send and receive information:

  • http://{BLOCKED}w.2waky.com/AWS{random number}.jsp?{random characters}

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.778.08
VSAPI PATTERN Date: 19 Jan 2011
VSAPI PATTERN Date: 1/19/2011 12:00:00 AM

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and terminate files detected as BKDR_CRYPT.DA

[ Learn More ]
  1. 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.
  2. 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 BKDR_CRYPT.DA. 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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