Feds face more complex cyberattacks

Read more details about the Symantec report

Attacks and probes of government networks are becoming more sophisticated, and hackers may be looking for backdoors into vulnerable computers, according to Symantec's latest Internet Security Threat Report.

The company's biannual update on cyberthreats is based on data gleaned from a broad sample of Symantec's private- and public-sector customers worldwide. Symantec's Managed Security Services and DeepSight Threat Management System detected the attacks between July 1 and Dec. 31, 2004.

During that period, the top attack in the U.S. government sector was a buffer overrun attack on Microsoft Windows' Local Security Authority Subsystem Service (LSASS), said Alfred Huger, senior director of engineering at Symantec. The top attacks were determined by the percentage of total attackers performing each attack.

The Sasser worm that began spreading in January 2003 is one way that attackers exploit the LSASS vulnerability.

According to the study, 12 percent of those who targeted government organizations attacked the weakness. Successfully exploiting the vulnerability could enable a remote attacker to execute malicious code and take over a compromised system.

Windows XP Service Pack 2 is supposed to mitigate that vulnerability, Huger said. But if an infection does take place, filtering can identify compromised computers and prevent further damage. That approach should be combined with stronger filtering between logical network segments to limit the infection's spread, the Symantec report states.

The second top attack on government networks, Domain Name System poisoning, is not seen as often in the private sector, Huger said. Such attackers target the DNS infrastructure of an organization, allowing them to redirect Web users to computers that they specify rather than the intended destinations.

DNS servers are key technologies that must be maintained properly, according to the report, which also emphasizes the importance of keeping software patches up-to-date.

Monitoring which ports attackers are targeting can give administrators and security analysts vital information on the nature and prevalence of the attacks. During the second half of 2004, the most widely targeted port was UDP 1434, which hosts Microsoft SQL Server. The port was the target of the original Slammer worm in 2003. To protect against that threat, Symantec officials recommend patching all SQL Server and Microsoft Desktop Engine installations appropriately.

The second and third most attacked ports — TCP 9898 and TCP 1023, respectively — indicate that hackers are attempting to look for backdoors into government systems, Huger said. Attacks on those ports did not show up as often in the private sector, he added.

Intruders expect to find "more useful, resalable data at government sites than on a commercial site, which might just have credit card numbers," said Alan Paller, director of research at the SANS Institute. Or intruders could be stockpiling compromised computers for later use, he said.