BKDR_PAPRAS.SMB


 ALIASES:

TrojanDownloader:Win32/Harnig.P (Microsoft); Downloader-AWM.gen.c (McAfee); Trojan.FakeAV!gen50 (Symantec); Packed.Win32.Krap.ao (Kaspersky); Packed.Win32.Krap.ao (v) (Sunbelt); Gen:Malware.Heur.bq0@berf0Bhi (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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

26,624 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

06 Jul 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.

Other System Modifications

This backdoor deletes the following files:

  • %Temp%\scs3.tmp
  • %Temp%\scs5.tmp
  • %Temp%\scs2.tmp
  • %Temp%\scs7.tmp
  • %Temp%\scs9.tmp
  • %Temp%\scsB.tmp
  • %Temp%\scs1.tmp
  • %Temp%\scs8.tmp
  • %Temp%\scsA.tmp
  • %Temp%\scsC.tmp
  • %Temp%\scs4.tmp
  • %Temp%\scs6.tmp
  • %Temp%\scs11.tmp
  • %Temp%\scs13.tmp
  • %Temp%\scsD.tmp
  • %Temp%\scsE.tmp
  • %Temp%\scsF.tmp
  • %Temp%\scs10.tmp
  • %Temp%\scs12.tmp
  • %Temp%\scs15.tmp
  • %Temp%\scs14.tmp
  • %Temp%\scs16.tmp
  • %System%\svchost.exe

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "svchost.exe"

(Note: The default value data of the said registry entry is iexplore.exe.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = "4117ed6"

(Note: The default value data of the said registry entry is 41107b81.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}y.com/pimuowecw/sjaipk.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/jjdlsnvtov.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/neipnvqx.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/kxszhbwdcj.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/lpkez.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/neygn.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/ofmupwryg.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/lpkezhfmu.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/vytxsmu.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/hytniqkszx.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/qdlsn.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/vvqkfy.php?adv=adv521
  • http://{BLOCKED}y.com/pimuowecw/ffaucji.php?{random characters}

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: Name = "svchost.exe"
      To: Name = ""iexplore.exe""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: ID = "4117ed6"
      To: ID = ""41107b81""

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR_PAPRAS.SMB. 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.

Step 4

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Temp%\scs3.tmp
  • %Temp%\scs5.tmp
  • %Temp%\scs2.tmp
  • %Temp%\scs7.tmp
  • %Temp%\scs9.tmp
  • %Temp%\scsB.tmp
  • %Temp%\scs1.tmp
  • %Temp%\scs8.tmp
  • %Temp%\scsA.tmp
  • %Temp%\scsC.tmp
  • %Temp%\scs4.tmp
  • %Temp%\scs6.tmp
  • %Temp%\scs11.tmp
  • %Temp%\scs13.tmp
  • %Temp%\scsD.tmp
  • %Temp%\scsE.tmp
  • %Temp%\scsF.tmp
  • %Temp%\scs10.tmp
  • %Temp%\scs12.tmp
  • %Temp%\scs15.tmp
  • %Temp%\scs14.tmp
  • %Temp%\scs16.tmp
  • %System%\svchost.exe


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