PE_BLACKRID.A

July 11, 2015
 ALIASES:

Virus:Win32/Delf.L (Microsoft); W32/Generic.Delphi.b (McAfee); W32.Lawker (Symantec); Virus.Win32.Delf.aa (Kaspersky); BehavesLike.Win32.Malware.see (mx-v) (Sunbelt); Worm/Delf.JV (AVG)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This file infector 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:

606,074 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Jul 2015

Arrival Details

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Network Detection = "%System%\ntdetect.exe"

Other System Modifications

This file infector deletes the following files:

  • %System%\AUTOEXEC.NT

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunOnceEx

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\McShield\Security

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\McShield\Performance

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\McShield

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Kavsvc\Enum

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Kavsvc\Security

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Kavsvc

Dropping Routine

This file infector drops the following files:

  • %System%\ntdetect.exe
  • %User Temp%\{malware path and file name}~.exe
  • %System%\temp$.txt
  • %User Temp%\temp.exe
  • %System%\com.dll

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.750

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

Restart in Safe Mode

[ Learn More ]

Step 3

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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Microsoft Network Detection = "%System%\ntdetect.exe"

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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%\ntdetect.exe
  • %User Temp%\{malware path and file name}~.exe
  • %System%\temp$.txt
  • %User Temp%\temp.exe
  • %System%\com.dll

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_BLACKRID.A. 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 6

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.

  • %System%\AUTOEXEC.NT

Step 7

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
    • RunOnce
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
    • RunOnceEx
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\McShield
    • Security
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\McShield
    • Performance
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • McShield
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Kavsvc
    • Enum
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Kavsvc
    • Security
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • Kavsvc


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