BKDR_PAPRAS.VI

October 09, 2012
 Analysis by: Kathleen Notario
 ALIASES:

Trojan Horse (Symantec); Trojan:Win32/Orsam!rts (Microsoft); Backdoor.Win32.Papras.den (Kaspersky); Generic BackDoor!dkd (Mcafee); Mal/PWS-II (Sophos)

 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 as a file that exports the functions of other malware/grayware. It 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:

60,928 bytes

File Type:

DLL

Initial Samples Received Date:

24 Aug 2011

Arrival Details

This backdoor arrives as a file that exports the functions of other malware/grayware.

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

Other System Modifications

This backdoor adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\AppDataLow

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.376.13

FIRST VSAPI PATTERN DATE:

24 Aug 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

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • In HKEY_CURRENT_USER\Software
    • AppDataLow

Step 4

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