BKDR_BZUB.KZ
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This backdoor may arrive as a file that exports functions used by other malware. It may be dropped by other malware.
It deletes registry entries, causing some applications and programs to not function properly.
It does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
It does not have any downloading capability.
TECHNICAL DETAILS
32,768 bytes
DLL
Yes
23 Aug 2013
Arrival Details
This backdoor may arrive as a file that exports functions used by other malware.
It may be dropped by other malware.
Installation
This backdoor drops the following copies of itself into the affected system:
- %User Temp%\{random digit}.dat
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- GDGSYDLYR_1848874853
Other System Modifications
This backdoor deletes the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
6E339765 =
Propagation
This backdoor does not have any propagation routine.
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Upload file
- Perform remote shell commands
It connects to the following websites to send and receive information:
- http://{BLOCKED}.{BLOCKED}.228.102:443/info.asp
Download Routine
This backdoor does not have any downloading capability.
Information Theft
This backdoor gathers the following data:
- Host Name
- User Name
- Drive and volume information
NOTES:
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.300
10.244.03
28 Aug 2013
10.245.00
29 Aug 2013
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
Scan your computer with your Trend Micro product and note files detected as BKDR_BZUB.KZ
Step 3
Restart in Safe Mode
Step 4
Search and delete the files detected as BKDR_BZUB.KZ
*Note: Some component files may be hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
To stop the malware/grayware from running when certain files are opened:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the Named input box, type the name of the file that was detected earlier.
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
For Windows Vista and Windows 7:
- Click Start>Computer.
- In the Search Computer input box, type the name of the file detected earlier, and press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BZUB.KZ. 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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