Virus.Win32.LAMER.F

 Analysis by: Khristian Joseph Morales

 ALIASES:

Virus.Win32.Lamer.cb (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Virus

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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

It prepends its codes to target files.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It does not have any backdoor routine.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size:

1,098,760 bytes

File Type:

EXE

File Compression:

Delphi

Memory Resident:

Yes

Initial Samples Received Date:

04 Nov 2021

Payload:

Drops files

Arrival Details

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

Installation

This Virus drops the following copies of itself into the affected system:

  • %System%\HelpMe.exe
  • {Drive Letter}\AutoRun.exe

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

It adds the following processes:

  • %System%\HelpMe.exe

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = Explorer.exe HelpMe.exe

It adds the following lines or registry entries as part of its routine:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • CheckedValue = 0

It drops the following file(s) in the Startup Items folder to enable its automatic execution at every system startup:

  • %User Startup%\Soft.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

File Infection

This Virus prepends its codes to target files.

It avoids infecting the following files:

  • %System%\HelpMe.exe

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

Propagation

This Virus drops copies of itself in the following drives:

  • Fixed
  • Network

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

open=AutoRun.exe
shell\1=Open
shell\1\Command=AutoRun.exe
shell\2\=Browser
shell\2\Command=AutoRun.exe
shellexecute=AutoRun.exe

Backdoor Routine

This Virus does not have any backdoor routine.

Rootkit Capabilities

This Virus does not have rootkit capabilities.

Download Routine

This Virus does not have any downloading capability.

Information Theft

This Virus does not have any information-stealing capability.

Other Details

This Virus does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

17.174.02

FIRST VSAPI PATTERN DATE:

05 Nov 2021

VSAPI OPR PATTERN File:

17.175.00

VSAPI OPR PATTERN Date:

06 Nov 2021

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TROJ.Win32.TRX.XXPE50FFF050

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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 NT\CurrentVersion\Winlogon
    • Shell = Explorer.exe HelpMe.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • CheckedValue = 0

Step 6

Search and delete these files

[ Learn More ]
There may be some files 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%\HelpMe.exe
  • %User Startup%\Soft.lnk
  • {Drive Letter}\AutoRun.exe

Step 7

Search and delete AUTORUN.INF files created by Virus.Win32.LAMER.F that contain these strings

[ Learn More ]
  • open=AutoRun.exe
  • shell\1=Open
  • shell\1\Command=AutoRun.exe
  • shell\2\=Browser
  • shell\2\Command=AutoRun.exe
  • shellexecute=AutoRun.exe

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Virus.Win32.LAMER.F. 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.


Did this description help? Tell us how we did.