Analysis by: Mark Joseph Manahan

ALIASES:

Mal/Generic-L (Sophos) ,Trojan horse Generic35.BQBZ (AVG) ,W32/Neurevt.AFC!tr (Fortinet) ,Trojan.Win32.Neurevt.afc (Kaspersky) ,Trojan:Win32/Neurevt.A (Microsoft) ,RDN/Generic.dx!c2o (McAfee) ,Win32/Neurevt.B trojan (Eset) ,Trojan.Ransomlock.G (Symantec) ,Generic (Panda) ,Trojan.Win32.Generic!BT (Sunbelt)

 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:
 INFORMATION EXPOSURE:

  • 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.

  TECHNICAL DETAILS

File Size: 397,312 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 Feb 2014
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:

  • %Program Files%\Common Files\openoffic0\{random}.exe
  • %All Users Profile\Application Data\openoffic0\{random}.exe"

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

It creates the following folders:

  • %All Users Profile%\Application Data\openoffic0
  • %Program Files%\Common Files\openoffic0

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

It injects codes into the following process(es):

  • explorer.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
openoffic = "%All Users Profile%\Application Data\openoffic0\{random}.exe"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
openoffic = "%All Users Profile%\Application Data\openoffic0\{random}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
openoffic = "%Program Files%\Common Files\openoffic0\{random}.exe"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
openoffic = "%Program Files%\Common Files\openoffic0\{random}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer
TaskbarNoNotification = "1"

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 / Update itself

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

  • http://{BLOCKED}rve.info/b/order.php

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}r.net/download/pts.exe - detected as TROJ_COINMINE.B
  • http://{BLOCKED}r.net/download/x86.exe - detected as TROJ_COINMINE.B

Information Theft

This Trojan retrieves the following information from the affected system:

  • Operating system version
  • Hardware Information (Power Status, Processor)
  • Installed FTP Softwares (CoreFTP,FileZilla,FlashFXP,FTP Commander,PuTTy,SmartFTP,WinSCP)
  • Installed Game Softwares (Steam, League of Legends,Origin, Blizzard, Origin, Runescape)
  • Installed Messenger (Skype)
  • Installed AV Products
  • Username
  • Default Browser
  • Dotnet Version
  • Java Version
  • IPs of recent RDP
  • Installed Softwares (Sysinternals, mIRC, Hex-Rays, Immunity Inc, CodeBlocks,7-Zip,PrestoSoft,Nmap,Perl,Visual C++, Wireshark, Visual Studio, VMWare, Inc.)

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

NOTES:

It queries the following registry key to get Microsoft Net Framework Version:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Net Framework setup\NDP

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

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor

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

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.602.02
FIRST VSAPI PATTERN DATE: 12 Feb 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

Remove the malware/grayware file dropped/downloaded by BKDR_NEUREVT.NST

    • TROJ_COINMINE.B

Step 3

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

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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.

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  • openoffic = "%All Users Profile%\Application Data\openoffic0\{random}.exe"
  • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  • openoffic = "%All Users Profile%\Application Data\openoffic0\{random}.exe"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  • openoffic = "%Program Files%\Common Files\openoffic0\{random}.exe"
  • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  • openoffic = "%Program Files%\Common Files\openoffic0\{random}.exe"
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
  • TaskbarNoNotification = "1"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Win7zip
  • Uuid = "{random values}"

Step 6

Reset Internet security settings

[ Learn More ]

Step 7

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%\Common Files\openoffic0
  • %All Users Profile%\Application Data\openoffic0

Step 8

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