Analysis by: Michael Cabel
 Modified by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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 propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

Ports: TCP Port 443, TCP Port 80 (HTTP)
File Size: Varies
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 01 Jun 2011
Payload: Connects to URLs/IPs

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.

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Enumerate processes
  • Start remote command prompt
  • Create a file for writing
  • Write to the opened file
  • Open/Execute a file
  • Read a part or an entire file
  • Close connection to C&C server
  • Delete a file
  • Terminate process
  • Enumerate drives and their types
  • List files in the current directory

It connects to the following websites to send and receive information:

  • {BLOCKED}.{BLOCKED}.149.100:443
  • mycount.{BLOCKED}e.com:443

Download Routine

This backdoor does not have any downloading capability.

Information Theft

This backdoor does not have any information-stealing capability.

NOTES:

This backdoor connects to its C&C servers through a proxy server at {BLOCKED}.{BLOCKED}.16.21:8080. It is typically installed as a service.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.196.06
FIRST VSAPI PATTERN DATE: 01 Jun 2011
VSAPI OPR PATTERN File: 8.197.00
VSAPI OPR PATTERN Date: 02 Jun 2011

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

Scan your computer with your Trend Micro product and note files detected as BKDR_PAPRAS.SMF

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the file detected as BKDR_PAPRAS.SMF

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PAPRAS.SMF. 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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