Analysis by: jasperm
ALIASES:

Symantec: Backdoor.Trojan; Microsoft: TrojanSpy:Win32/Ursnif; Kaspersky: Backdoor.Win32.Papras.nl

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This malicious DLL file connects to command and control (C&C) servers and sends an HTTP GET request.

It performs backdoor routines. Specifically, it steals and clears cookies. It downloads and executes files from the server. It reboots the system. It also takes screenshots.

This backdoor may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites. However, as of this writing, the said sites are inaccessible.

It attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

  TECHNICAL DETAILS

File Size: 47,616 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 21 Oct 2010
Payload: Steals information, Connects to URLs/Ips

Arrival Details

This backdoor may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

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

Installation

This backdoor injects threads into the following normal process(es):

  • IEXPLORE.EXE
  • FIREFOX.EXE
  • CHROME.EXE
  • OPERA.EXE
  • SAFARI.EXE

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SessionManager\AppCertDlls
{value} = {malware path and file name}.DLL

Information Theft

This backdoor attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

Other Details

This backdoor does the following:

  • It performs the following backdoor routines:
    • Steals cookies
    • Clears cookies
    • Downloads and executes files from the server
    • Reboots system
    • Takes screenshots
  • This malicious DLL file connects to the following C&C server and sends an HTTP GET request:
    • {BLOCKED}.{BLOCKED}.215.130
    • {BLOCKED}.{BLOCKED}.207.151

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.559.80
VSAPI PATTERN Date: 21 Oct 2010
VSAPI PATTERN Date: 10/21/2010 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

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

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ 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.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\AppCertDlls
    • {value} = {malware path and file name}.DLL

Step 5

Search and delete the file detected as BKDR_PAPRAS.BX

[ 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.


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