BKDR_POISON.CYA
Backdoor.Win32.Agent.cjqi (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
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.
It deletes itself after execution.
TECHNICAL DETAILS
190,976 bytes
EXE
No
18 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:
- %User Profile%\Microsoft PA\SxS.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It creates the following folders:
- %User Profile%\Microsoft PA
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\CLASSES\
FAST
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent\Post Platform
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent\Post Platform
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
FAST
CLSID = "{random values}"
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}.16.143/update?id=0ae9ec88
- http://{BLOCKED}.16.143/update?id=0a59ec88
- http://{BLOCKED}.16.143/update?id=0666ec88
- http://{BLOCKED}.16.143/update?id=05dcec88
- http://{BLOCKED}.16.143/update?id=01ceec88
- http://{BLOCKED}.16.143/update?id=09c6ec88
- http://{BLOCKED}.16.143/update?id=13acec88
- http://{BLOCKED}.16.143/update?id=1429ec88
- http://{BLOCKED}.16.143/update?id=1333ec88
- http://{BLOCKED}.16.143/update?id=15e1ec88
- http://{BLOCKED}.16.143/update?id=103aec88
- http://{BLOCKED}.16.143/update?id=10a3ec88
- http://{BLOCKED}.16.143/update?id=0f97ec88
- http://{BLOCKED}.16.143/update?id=1a3eec88
- http://{BLOCKED}.16.143/update?id=04c1ec88
It deletes itself after execution.
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
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\Software\CLASSES
- FAST
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\User Agent
- Post Platform
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent
- Post Platform
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\Classes\FAST
- CLSID = "{random values}"
Step 4
Search and delete this folder
- %User Profile%\Microsoft PA
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_POISON.CYA. 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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