BKDR_PCCLIENT.MD

October 12, 2012
 ALIASES:

Trojan:Win32/AgentBypass.gen!K, Backdoor:Win32/Small (Microsoft); BackDoor-CKB.dr (McAfee); Infostealer (Symantec); PAK:PE-Armor, Trojan-Dropper.Win32.Agent.rz (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Backdoor.Hupigon.50017 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size:

18,253 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Apr 2012

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.

Installation

This backdoor drops the following copies of itself into the affected system:

  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Dropping Routine

This backdoor drops the following files:

  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.del
  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.asf
  • %System%\00676.dat
  • %System%\01472.dat
  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://www.{BLOCKED}er.com/4y.txt
  • http://{BLOCKED}8.36.158:80/30010009

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.del
  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.asf
  • %System%\00676.dat
  • %System%\01472.dat
  • %System%\2f50b8af679b5ce9bed4721400728124497d906f_31f832c0d49126651fa799a79e94.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR_PCCLIENT.MD. 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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