BKDR_NEUREVT.JSJ

 Analysis by: Rhena Inocencio

 ALIASES:

a variant of Win32/Kryptik.BAJC trojan (NOD32), W32/Krptik.QWR!tr (Fortinet)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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 executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It modifies the Internet Explorer Zone Settings.

It retrieves specific information from the affected system.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

354,304 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 May 2013

Payload:

Compromises system security, Terminates processes, Steals information

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 drops the following copies of itself into the affected system:

  • {Path}\jewsdidit{number}\{random file name 1}.exe

It drops the following non-malicious file:

  • {Path}\jewsdidit{number}\{random file name 2}.txt

It injects codes into the following process(es):

  • wuauclt.exe

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
jewsdidit = "{Path}\jewsdidit{number}\{random file name 1}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
jewsdidit = "{Path}\jewsdidit{number}\{random file name 1}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\CLSID\{CLSID}\
{random value}\CG1
HAL = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Win7zip
Uuid = "{random values}"

Backdoor Routine

This Trojan executes the following commands from a remote malicious user:

  • Download and execute files
  • Perform Slowloris flooding
  • Execute shell commands
  • Copy itself in removable drives
  • Open a URL
  • Uninstall itself

It connects to the following websites to send and receive information:

  • {BLOCKED}y.{BLOCKED}s.cat/h/order.php
  • {BLOCKED}y.{BLOCKED}s.es/h/order.php
  • {BLOCKED}y.{BLOCKED}t.net/h/order.php

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Information Theft

This Trojan retrieves the following information from the affected system:

  • Operating system version
  • CPU information
  • Information on installed FTPs
  • Installed applications

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • update.microsoft.com
  • microsoft.com
  • windowsupdate.microsoft.com
  • google.com

It deletes the initially executed copy of itself

NOTES:

{Path} can be any of the following:

  • %All Users Profile%
  • %Program Files%\Common Files

It disables the following antivirus-related applications by adding the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\{application}
Debugger = "{random characters}_.exe"

  • a2guard.exe
  • a2service.exe
  • a2start.exe
  • adaware.exe
  • ALUpdate.exe
  • arcaclean.exe
  • avastsvc.exe
  • avastui.exe
  • avcenter.exe
  • AVENGINE.exe
  • avgcfgex.exe
  • avgdiagex.exe
  • avgidsagent.exe
  • avgmfapx.exe
  • avgnt.exe
  • avguard.exe
  • avgui.exe
  • avgupd.exe
  • avgwdsvc.exe
  • AVK.exe
  • AVKTray.exe
  • avshadow.exe
  • BgScan.exe
  • BullGuard.exe
  • BullGuardBhvScanner.exe
  • BullGuardScanner.exe
  • BullGuardUpdate.exe
  • BullGuardUpdate2.exe
  • ccsvchst.exe
  • ccupdate.exe
  • CLPSLA.exe
  • coreFrameworkHost.exe
  • coreServiceShell.exe
  • egui.exe
  • ekrn.exe
  • epavjobs.exe
  • ForceField.exe
  • FProtTray.exe
  • FPWin.exe
  • fshoster32.exe
  • GDFirewallTray.exe
  • GDSC.exe
  • K7TSUpdT.exe
  • mbam.exe
  • mbamgui.exe
  • mcagent.exe
  • McPvTray.exe
  • mcshell.exe
  • mcshield.exe
  • McSvHost.exe
  • McUICnt.exe
  • mcupdate.exe
  • mcupdmgr.exe
  • MSASCui.exe
  • MsMpEng.exe
  • msseces.exe
  • niu.exe
  • op_mon.exe
  • pctsAuxs.exe
  • pctsGui.exe
  • pctsSvc.exe
  • PSANHost.exe
  • PSUAService.exe
  • PSUNMain.exe
  • RavMonD.exe
  • rcfp.exe
  • rsmain.exe
  • RsMgrSvc.exe
  • RsTray.exe
  • SBAMTray.exe
  • sbamui.exe
  • sguardxup.exe
  • starter_avp.exe
  • symerr.exe
  • uiSeAgnt.exe
  • uiWatchDog.exe
  • Update.exe
  • update_tmp.exe
  • updater.exe
  • Upgrader.exe
  • usrreq.exe
  • uWinMgr.exe
  • WRSA.exe
  • zatray.exe

It attempts to gather account information from the following applications:

  • CoreFTP
  • FileZilla
  • FlashFXP
  • FTP Commander
  • PuTTY
  • Skype
  • SmartFTP
  • WinSCP

It queries the following registry key to get the processor information:

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.902.07

FIRST VSAPI PATTERN DATE:

08 May 2013

VSAPI OPR PATTERN File:

9.903.00

VSAPI OPR PATTERN Date:

08 May 2013

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

Scan your computer with your Trend Micro product and note files detected as BKDR_NEUREVT.JSJ

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 NT\CurrentVersion\Image File Execution Options\{application}
    • Debugger = "{random characters}_.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • jewsdidit = "{Path}\jewsdidit{number}\{random filename 1}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • jewsdidit = "{Path}\jewsdidit{number}\{random filename 1}.exe"
  • In HKEY_CURRENT_USER\CLSID\{CLSID}\{random value}\CG1
    • HAL = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Win7zip
    • Uuid = "{random values}"

Step 5

Search and delete this file

[ Learn More ]

There may be some component 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.
  • {Path}\jewsdidit{number}\{random file name 2}.txt

Step 6

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