Damage
Distribution
- Ports: UDP port 1434. The worm continuously sends traffic to randomly generated IP addresses, attempting to send itself to hosts running the Microsoft SQL Server Resolution Service, and that, therefore listens on that particular port.
When W32.SQLExp.Worm attacks a vulnerable system, it does the following:
- Sends itself to the SQL Server Resolution Service, which listens on UDP port 1434.
- Takes advantage of a buffer overflow vulnerability that allows a portion of system memory to be overwritten. When the worm does this, it runs in the same security context as the SQL Server service.
- Calls the Windows API function, GetTickCount, and uses the result as a seed to randomly generate IP addresses.
- Opens a socket on the infected computer and attempts to repeatedly send itself to UDP port 1434 on the IP addresses it has generated, by using an ephemeral source port. Because the worm does not selectively attack the hosts in the local subnet, large amounts of traffic are the result.
For more information about the vulnerability that this worm exploits, refer to the following article at:
http://securityresponse.symantec.com/avcenter/security/Content/2270.html.
Symantec Gateway Security
Symantec has released updates for Symantec Gateway Security via LiveUpdate. Additionally, you may click here to learn about limiting the ingress traffic for W32.SQLExp.Worm using Symantec Gateway Security.
Enterprise Security Manager
Symantec has released an Enterprise Security Manager policy for this threat. Click here for more information.
Intruder Alert
Symantec has released an Intruder Alert 3.5/3.6 Integration Policy for NetProwler 3.5x. Click here for more information.
NetProwler
Symantec has released Security Update 22 for NetProwler 3.5.1, which includes a detection for W32.SQLExp.Worm. Click here for more information.
Symantec Enterprise Firewall, Symantec VelociRaptor, Symantec Raptor Firewall
Click here to learn about limiting the ingress traffic for W32.SQLExp.Worm using Symantec's Enterprise Firewall, VelociRaptor, and Raptor products.
ManHunt
ManHunt Protocol Anomaly Detection technology detects the traffic generated by this threat as a UDP flood. To specifically detect this threat as W32.SQLExp.Worm, Symantec recommends that users of the ManHunt product activate the HYBRID MODE function and apply the following custom rule:
*******************start file********************
#
#Variables need to be set dependent on the users network. Below are examples on how to set
# variable. For more information see ManHunt Administrative Guide: Appendix A.
#
#var EXTERNAL_NET 192.168.1.0/24
#
#
#
var EXTERNAL_NET any
var HOME_NET any
#
#
#
alert udp $EXTERNAL_NET any -> $HOME_NET 1434 (msg:"W32.SQLEXP.Worm propagation"; content:"|68 2E 64 6C 6C 68 65 6C 33 32 68 6B 65 72 6E|"; content:"|04|"; offset:0; depth:1;)
*************EOF*********************
For more information on how to create custom signatures, refer to the "ManHunt Administrative Guide: Appendix A Custom Signatures for HYBRID Mode."
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":
- Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
- If a blended threat
exploits one or more network services, disable, or block access to, those services until a patch is applied.
Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
Removal Tool
Symantec has provided a tool to remove the infections of W32.SQLexp.Worm. Click here to obtain the tool. Try this tool first, as it is the easiest way to remove this threat. Because the worm resides in memory only and is not written to disk, the virus definitions do not detect this threat. Customers are recommended to follow the measures described in this document to control with this threat.
Additional information:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0649
http://www.cert.org/advisories/CA-2002-22.html
http://online.securityfocus.com/bid/5310
http://online.securityfocus.com/bid/5311
http://www.microsoft.com/technet/security/bulletin/ms02-039.asp
http://www.microsoft.com/technet/security/bulletin/MS02-061.asp
http://www.cisco.com/warp/public/707/cisco-sa-20030126-ms02-061.shtml
Write-up by: Douglas Knowles
