TROJ_OTOIT.USVP


 ALIASES:

Backdoor:MSIL/Noancooe.C (Microsoft); Trojan.Nancrat (Symantec); Trojan horse SCGeneric_c3.ATXT (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

815,409 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Aug 2017

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.

Installation

This Trojan creates the following folders:

  • %Program Files%\%LocalAppData%
  • %Program Files%\%LocalAppData%\temp
  • %Program Files%\%LocalAppData%\temp\prr
  • %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
  • %Program Files%\NAT Monitor
  • %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
  • %User Profile%\Logs\Wilbert

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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
WindowsUpdate = "%User Temp%\prr\hrr-tci"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NAT Monitor = "%Program Files%\NAT Monitor\natmon.exe"

Other System Modifications

This Trojan deletes the following files:

  • %Program Files%\%LocalAppData%\temp\prr\PUBJS
  • %User Profile%\NAT Monitor\natmon.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Dropping Routine

This Trojan drops the following files:

  • __tmp_rar_sfx_access_check_35625
  • tmo.pdf
  • hrr-tci
  • eis.exe
  • qfc.txt
  • ufu.dat
  • wbh.mp3
  • ncn.dat
  • fnm.ico
  • oun.txt
  • met.bmp
  • dnp.docx
  • qnh.xl
  • mqi.ico
  • xvr.ico
  • tbp.bmp
  • alj.bmp
  • fhc.mp3
  • tvf.txt
  • jof.txt
  • ihb.mp3
  • ktv.jpg
  • leq.docx
  • pbw.xl
  • svf.mp3
  • uti.xl
  • lxo.xl
  • qqa.ico
  • qui.txt
  • cqe.docx
  • puu.xl
  • vmx.bmp
  • hcm.bmp
  • seb.mp4
  • cxm.dat
  • iim.txt
  • tdm.pdf
  • eaa.dat
  • lua.mp3
  • dwx.mp3
  • obw.txt
  • mdj.mp4
  • oob.bmp
  • rgv.bmp
  • dcd.bmp
  • tcl.dat
  • ovr.bmp
  • tvv.ico
  • tbu.mp4
  • %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
  • %User Temp%\RegSvcs.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • WindowsUpdate = "%User Temp%\prr\hrr-tci"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • NAT Monitor = "%Program Files%\NAT Monitor\natmon.exe"

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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.
  • __tmp_rar_sfx_access_check_35625
  • tmo.pdf
  • hrr-tci
  • eis.exe
  • qfc.txt
  • ufu.dat
  • wbh.mp3
  • ncn.dat
  • fnm.ico
  • oun.txt
  • met.bmp
  • dnp.docx
  • qnh.xl
  • mqi.ico
  • xvr.ico
  • tbp.bmp
  • alj.bmp
  • fhc.mp3
  • tvf.txt
  • jof.txt
  • ihb.mp3
  • ktv.jpg
  • leq.docx
  • pbw.xl
  • svf.mp3
  • uti.xl
  • lxo.xl
  • qqa.ico
  • qui.txt
  • cqe.docx
  • puu.xl
  • vmx.bmp
  • hcm.bmp
  • seb.mp4
  • cxm.dat
  • iim.txt
  • tdm.pdf
  • eaa.dat
  • lua.mp3
  • dwx.mp3
  • obw.txt
  • mdj.mp4
  • oob.bmp
  • rgv.bmp
  • dcd.bmp
  • tcl.dat
  • ovr.bmp
  • tvv.ico
  • tbu.mp4
  • %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
  • %User Temp%\RegSvcs.exe

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Program Files%\%LocalAppData%
  • %Program Files%\%LocalAppData%\temp
  • %Program Files%\%LocalAppData%\temp\prr
  • %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
  • %Program Files%\NAT Monitor
  • %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
  • %User Profile%\Logs\Wilbert

Step 6

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

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Program Files%\%LocalAppData%\temp\prr\PUBJS
  • %User Profile%\NAT Monitor\natmon.exe


Did this description help? Tell us how we did.