ALIASES:

Prorat

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

PRORAT is a family of backdoors that serves as a remote administration tool (RAT). Variants of this malware family first appeared in 2005.

It opens random ports to establish connection with a remote attacker. Once a connection is established, the remote attacker can execute commands such as creating/opening/closing/deleting files, monitoring visited websites, and retrieving system information among others. It also monitors user names and passwords in the following messaging applications:

  • ICQ

  • MSN Messenger

  • NetMeeting

  • Outlook Express

  • Yahoo! Messenger

It also obtains email addresses by accessing the following:

  • Messenger Address Book

  • Outlook Address Book

  • Trillian Address Book

PRORAT also steals information such as the retrieved data stated above. It sends the stolen information to certain IPs and URLs.

  TECHNICAL DETAILS

Memory Resident: Yes
Payload: Connects to URLs/IPs, Steals information

Installation

This backdoor drops the following files:

  • %System%\reginv.dll
  • %System%\winkey.dll
  • %System%\drivers\oreans32.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following copies of itself into the affected system:

  • %System%\fservice.exe
  • %System%\sservice.exe
  • %Windows%\services.exe
  • %Windows%\system\sservice.exe
  • %Windows%\winlogon.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
DirectX For Microsoft® Windows = "%System%\fservice.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{5Y99AE78-58TT-11dW-BE53-Y67078979Y}
StubPath = "%Windows%\system\sservice.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "Explorer.exe %System%\fservice.exe"

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

Other System Modifications

This backdoor deletes the following files:

  • %System%\Restore\MachineGuid.txt

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Bulas = "1"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
FW_KILL = "1"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
XP_FW_Disable = "1"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
XP_SYS_Recovery = "1"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
ICQ_UIN = ""

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Kurban_Ismi = "bdsdo`jr`o"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Mail = "btsdmhfiu^Ainul`hm/bnl"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Online_List = ""

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Port = "4001"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Sifre = "0370"

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
Hata = ""

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings
KSil = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Bulas = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
FW_KILL = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
XP_FW_Disable = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
XP_SYS_Recovery = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
ICQ_UIN = "084/41/051/069"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Kurban_Ismi = "whbuhl"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Mail = "`cs`i`ljdsoAinul`hm/ed"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Online_List = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Port = "4001"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Sifre = "032547"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Hata = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
KSil = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
ICQ_UIN2 = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
LanNotifie = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
Tport = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings
ServerVersionInt = "19"

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SystemRestore
DisableSR = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\sr
Start = "4"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\sr\Parameters
FirstRun = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\srservice
Start = "4"

(Note: The default value data of the said registry entry is 2.)

It adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft DirectX

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag

HKEY_CURRENT_USER\Software\Microsoft DirectX\
WinSettings

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT Script Host\Microsoft DxDiag\WinSettings

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{5Y99AE78-58TT-11dW-BE53-Y67078979Y}

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{5Y99AE78-58TT-11dW-BE53-Y67078979Y}

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile\AuthorizedApplications\
List
%Windows%\winlogon.exe = "%Windows%\winlogon.exe:*:Disabled:winlogon"

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.23.201
  • {BLOCKED}u.edu.tr
  • {BLOCKED}a.edu.tr
  • {BLOCKED}i.edu.tr
  • {BLOCKED}e.edu.tr