WORM_HTACOPY.SMJ

 Analysis by: Christian Noel Olalia

 ALIASES:

HTML/Agent.AG trojan (ESET), Trojan.JS.Agent.cdc (Kaspersky), JS/Agent.AR (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware


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.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size:

5,924 bytes

File Type:

HTA

Memory Resident:

Yes

Initial Samples Received Date:

01 Mar 2018

Payload:

Drops files

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:

  • %Application Data%\Microsoft\Windows\Printer Shortcuts\Default Printer.hta

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

Autostart Technique

This Worm drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • Default Printer.lnk
  • {Random Application Name}.lnk

Other System Modifications

This Worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
htafile\DefaultIcon
= %SystemRoot%\System32\imageres.dll,-72

Propagation

This Worm drops the following copy of itself in all physical and removable drives:

  • {Drive Letter}:\foto buena mia (NO BORRAR NUNCA MUY IMPORTANTE!!!).hta

Backdoor Routine

This Worm does not have any backdoor routine.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

10.693.00

FIRST VSAPI PATTERN DATE:

28 Mar 2014

VSAPI OPR PATTERN File:

10.694.00

VSAPI OPR PATTERN Date:

29 Mar 2014

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\Classes\htafile\DefaultIcon
    • = %SystemRoot%\System32\imageres.dll,-72

Step 5

Search and delete this file

[ 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.
  • Default Printer.lnk
  • {Random Application Name}.lnk

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_HTACOPY.SMJ. 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 7

Scan your computer with your Trend Micro product to delete files detected as WORM_HTACOPY.SMJ. 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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