BKDR_NEUREVT.AA

This backdoor 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.

Arrival Details

This backdoor 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 backdoor drops the following copies of itself into the affected system and executes them:

• %Program Files%\Common Files\Flash Update Client.{2227A280-3AEA-1069-A2DE-08002B30309D}\{random file name}.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 adds the following processes:

• wuauclt.exe

It stays memory-resident by injecting codes into the following processes:

• created wuauclt.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Flash Update Client = "%Program Files%\Common Files\Flash Update Client.{2227A280-3AEA-1069-A2DE-08002B30309D}\{random file name}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Flash Update Client = "%Program Files%\Common Files\Flash Update Client.{2227A280-3AEA-1069-A2DE-08002B30309D}\{random file name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Flash Update Client = "%Program Files%\Common Files\Flash Update Client.{2227A280-3AEA-1069-A2DE-08002B30309D}\{random file name}.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CLASSES_ROOT\CLSID\{CLSID}

HKEY_CLASSES_ROOT\CLSID\{CLSID}\
0BAC02C7

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\TaskManager

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\TaskManager
Task Service ID = "{hex value}"

It modifies the following registry entries:

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

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\
Java Update\Policy
EnableJavaUpdate = "0"

(Note: The default value data of the said registry entry is 1.)

Backdoor Routine

This backdoor 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 URL(s) to send and receive commands from a remote malicious user:

• http://{BLOCKED}tingprotection.info/icool/order.php

Information Theft

This backdoor gathers the following data:

• Hardware information
• Installed FTP software (CoreFTP, FileZilla, Flash FXP, FTP Commander, PuTTy, Smart FTP, WinSCP)
• Java version
• .NET version
• Installed messaging software (Skype)
• Installed anti-malware products
• Installed browser
• Operating system version
• Installed software (Sysinternals, mIRC, Hex-Rays, Immunity Inc, CodeBlocks, 7-Zip, PrestoSoft, Nmap, Perl)

NOTES:

It creates the following registry to lower security settings:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
2500 = "3"

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

where {application} are as follows:

• a2guard.exe
• a2service.exe
• a2start.exe
• adaware.exe
• ALUpdate.exe
• arcaclean.exe
• avastsvc.exe
• avastui.exe
• avcenter.exe
• AVENGINE.exe
• avgcfgex.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
• drstrui.exe
• egui.exe
• ekrn.exe
• epavjobs.exe
• ForceField.exe
• FProtTray.exe
• FPWin.exe
• fshoster32.exe
• GDFirewallTray.exe
• GDSC.exe
• hijackthis.exe
• housecalllauncher.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
• spybotsd.exe
• starter_avp.exe
• symerr.exe
• uiSeAgnt.exe
• uiUpdateTray.exe
• uiWatchDog.exe
• Update.exe
• update_tmp.exe
• updater.exe
• Upgrader.exe
• usrreq.exe
• uWinMgr.exe
• WRSA.exe
• zatray.exe