Analysis by: Rhena Inocencio
ALIASES:

VirTool:INF/Autorun!rfn (Microsoft), Worm.Win32.AutoRun.hxb (Kaspersky), a variant of Win32/AutoRun.Agent.ACR worm (ESET)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm arrives via removable drives. It 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: 197,632 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Apr 2016

Arrival Details

This worm arrives via removable drives.

It 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 worm drops the following copies of itself into the affected system and executes them:

  • %System%\LoadPowerProfile.exe

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

It drops the following files:

  • %System%\autorun.inf
  • {drive letter}:\autorun.inf

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
LoadPowerProfile = "%System%\LoadPowerProfile.exe"

Other System Modifications

This worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {drive letter}:\LoadPowerProfile.exe

Other Details

This worm connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.233.83:6606

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.466.01
FIRST VSAPI PATTERN DATE: 14 Apr 2016
VSAPI OPR PATTERN File: 12.467.00
VSAPI OPR PATTERN Date: 15 Apr 2016

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

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 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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • LoadPowerProfile = "%System%\LoadPowerProfile.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallOverride = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusOverride = "1"
RESTORE
  • Close Registry Editor.

    • Step 5

    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%\autorun.inf
    • {drive letter}:\autorun.inf

    Step 6

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_OTORUN.LS. 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.


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