BKDR_PEPI.TEYGV

February 18, 2014
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

a variant of Win32/Agent.PZM trojan (NOD32)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 does not have any file infection routine.

It does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

115,712 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

15 Feb 2014

Payload:

Compromises system security, Connects to URLs/IPs, Collects system information

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.

Infection Points

This backdoor does not have any file infection routine.

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • Download files
  • Access files
  • Create Pipe (to communicate with its components' processes)

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}c.{BLOCKED}s.net

It posts the following information to its command and control (C&C) server:

  • Physical Drive(s) information
  • SCSI information
  • CPU information (speed, vendor ID and feature flags)

However, as of this writing, the said sites are inaccessible.

NOTES:

After creating an anonymous pipe, it will perform the following routine:

  1. It searches for %System%\wmiprop.exe.
  2. Once found, it will execute the said file. In turn, the newly created process will now handle the data received from the created pipe.
  3. If not, it will instead execute %System%\cmd.exe (Windows Command Prompt) to handle the data from the pipe. Hence, a remote shell is initialized.

  SOLUTION

Minimum Scan Engine:

9.700

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

Search and delete these files

[ Learn More ]
There may be some 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%\wmiprop.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR_PEPI.TEYGV. 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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