Analysis by: Francesca Villasanta
ALIASES:

Trojan.Win32.AutoRun.al (KASPERSKY); Worm:VBS/Autorun!inf (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

It automatically executes files when a user opens a drive.

  TECHNICAL DETAILS

File Size: 103 bytes
File Type: INF
Memory Resident: No
Initial Samples Received Date: 08 Aug 2023
Payload: Executes files

Arrival Details

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

Propagation

The said .INF file contains the following strings:

UT 9
[autorun]
open=wscript.exe .\.vbs
shell\open\command=wscript.exe .\.vbs
shell\open\default=1

Other Details

This Trojan automatically executes the following files when a user opens a drive:

  • {Drive Letter}:\.vbs

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.620.04
FIRST VSAPI PATTERN DATE: 08 Aug 2023
VSAPI OPR PATTERN File: 18.621.00
VSAPI OPR PATTERN Date: 09 Aug 2023

Step 1

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 2

Search and delete AUTORUN.INF files created by Trojan.INF.AUTORUN.NP that contain these strings

[ Learn More ]
  • UT 9
  • [autorun]
  • open=wscript.exe .\.vbs
  • shell\open\command=wscript.exe .\.vbs
  • shell\open\default=1

Step 3

Scan your computer with your Trend Micro product to delete files detected as Trojan.INF.AUTORUN.NP. 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 the following Trend Micro Support pages for more information:


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