W32.SQLExp.Worm

W32.SQLExp.Worm is a worm that targets the systems running Microsoft SQL Server 2000, as well as Microsoft Desktop Engine (MSDE) 2000. The worm sends 376 bytes to UDP port 1434, the SQL Server Resolution Service Port. The worm has the unintended payload of performing a Denial of Service attack due to the large number of packets it sends. Symantec Security Response strongly recommends that all the users of either Microsoft SQL Server 2000 or MSDE 2000 audit their computers for the vulnerabilities that are referred to in Microsoft Security Bulletin MS02-039 and Microsoft Security Bulletin MS02-061. Symantec Security Response also recommends that you: Configure perimeter devices to block the ingress UDP traffic to port 1434 from untrusted hosts. Block the egress UDP traffic from your network to the destination port 1434. For more information on the SQL outbreak, refer to the Web cast at: https://enterprisesecurity.symantec.com/Content/webcastarchive.cfm?SSL=YES&EID=0&webcastID=45. 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. Symantec Security Response recommends that you follow the measures described in this document to deal with this threat. Please refer to the Technical Details section below for information on how to configure the Symantec products to detect this threat.
Removal tool link: http://securityresponse.symantec.com/avcenter/venc/data/w32.sqlexp.worm.removal.tool.html

Also Known As:	SQL Slammer Worm [ISS], DDOS.SQLP1434.A [Trend], W32/SQLSlammer [McAfee], Slammer [F-Secure], Sapphire [eEye], W32/SQLSlam-A [Sophos]
Type:	Worm
Infection Length:	376 bytes
Systems Affected:	Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Me
Systems Not Affected:	DOS, Linux, Macintosh, Novell Netware, OS/2, UNIX, Windows 3.x
CVE References:	CAN-2002-0649

Wild Number of infections: More than 1000 Number of sites: More than 10 Geographical distribution: High Threat containment: Easy Removal: Easy

Threat Metrics Wild: Low Damage: Low Distribution: Medium

Damage

• Payload:
  • Degrades performance: May affect network availability

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.

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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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

Revision History:

June 6, 2004: Downgraded from Category 3 to Category 2 based on decreased activity.

Write-up by: Douglas Knowles