BKDR_PHDET.AR
Backdoor:Win32/Phdet.gen!A (Microsoft); Generic BackDoor!d2f (McAfee); Trojan.Gen.2 (Symantec); PAK:UPX (Kaspersky); Trojan.Win32.Kryptik.vke (v) (Sunbelt); Trojan.Generic.KDV.408569 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
37,888 bytes
EXE
Yes
03 Jun 2012
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:
- %System%\mssrv32.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.)
Autostart Technique
This backdoor registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msupdate
Other System Modifications
This backdoor adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
ImagePath = "%System%\mssrv32.exe"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
DisplayName = "Microsoft security update service"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
Description = "This service downloading and installing Windows security updates"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\msupdate
Type = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AFD\Parameters
DisableRawSecurity = "1"
Other Details
This backdoor connects to the following possibly malicious URL:
- http://sharp.{BLOCKED}r.ru115566335544/stat.php
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Delete this registry key
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\SYSTEM\CurrentControlSet\Services
- msupdate
Step 4
Delete this registry value
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\SYSTEM\ControlSet001\Services\msupdate
- ImagePath = "%System%\mssrv32.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- DisplayName = "Microsoft security update service"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- Description = "This service downloading and installing Windows security updates"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- ObjectName = "LocalSystem"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- Start = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\msupdate
- Type = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AFD\Parameters
- DisableRawSecurity = "1"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PHDET.AR. 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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