BKDR_PSYRAT.B
Backdoor.Win32.Agent.ju (Kaspersky), a variant of Win32/Agent.OXR (ESET)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This backdoor may be unknowingly downloaded by a user while visiting malicious websites.
It connects to a website to send and receive information.
TECHNICAL DETAILS
5,632 bytes
EXE
Yes
29 Aug 2011
Arrival Details
This backdoor may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This backdoor drops the following copies of itself into the affected system:
- %System%\winhost.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
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\Run
Windows Host = "%System%\winhost.exe"
Backdoor Routine
This backdoor connects to the following websites to send and receive information:
- http://{BLOCKED}main.com/log.php
As of this writing, the said servers are currently inaccessible.
SOLUTION
9.700
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
Restart in Safe Mode
Step 3
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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Host = "%System%\winhost.exe"
- Windows Host = "%System%\winhost.exe"
Step 4
Search and delete these files
- "%System%\winhost.exe"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PSYRAT.B. 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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