WORM_PRASH.B
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This worm attempts to get a list of previous connections from an infected machine. It then checks the port of the remote server where the infected machine tries to connect. If the port is 1433, it launches an SQL Server attack. If the port is 445, it launches a Server Message Block (SMB) attack. It also exploits certain vulnerabilities to download other malware to other systems in the remote server it is trying to attack.
This worm 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
Arrival Details
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Download Routine
This worm connects to the following URL(s) to download its configuration file:
- http://soft.{BLOCKED}4.info/history/list.asp - encrypted configuration file
- http://{BLOCKED}s.into4.info/list.asp - encrypted configuration file
- http://cc.{BLOCKED}4.info/geturl.asp - contains list of URLs
NOTES:
If this worm is running under Windows XP, it prevents DDOS by checking if the connection speed is greater than 128 Kbps. If the speed is greater than 128 Kbps, it terminates the process with the highest bandwidth consumption. It also terminates processes with more than 5 network connections.
It attempts to get a list of previous connections from an infected machine. It then checks the port of the remote server where the infected machine tries to connect. If the port is 1433, it launches an SQL Server attack. If the port is 445, it launches a Server Message Block (SMB) attack. It exploits the following vulnerabilities to download other malware to other computers in the remote server it is trying to attack:
- (MS08-067) Vulnerability in Server Service Could Allow Remote Code Execution (958644)
- Microsoft SQL Server 'sa' Login With 'Null' Password Vulnerability
It makes the targetted computer access the following FTP sites to download files:
- ftp://{BLOCKED}i.in.into4.info
- ftp://to.{BLOCKED}a.com
As of this writing, the following files are downloaded:
- A08.exe - detected by Trend Micro as BKDR_RBOT.SMB
- B08.exe
- C001.exe - detected by Trend Micro as TROJ_AGENT.AZD
- G001.exe
- J001.exe
It then executes the downloaded files. As a result, routines of the downloaded files are exhibited on the affected system. Note that the downloaded files could change anytime.
This malware is typically installed as a service.
SOLUTION
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 3
Scan your computer with your Trend Micro product and note files detected as WORM_PRASH.B
Step 4
Restart in Safe Mode
Step 5
Search and delete the file detected as WORM_PRASH.B
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_PRASH.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.
Step 7
Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.
Did this description help? Tell us how we did.