The U.S. Navy confirmed Tuesday that its multibillion-dollar Navy/Marine Corps Intranet (N/MCI) has been taken off-line by what could be a combined onslaught of the Blaster worm variant and Sobig.F Internet worms, which are spreading fast.
A U.S. Navy spokesman said the details of the network's problems are still coming in and that it is unclear whether one or both worms were responsible for the failure. Navy officials are holding an emergency meeting to study the problem.
N/MCI is a US$6.9 billion IT outsourcing contract, often referred to as seat management, that will give the Navy and Marine Corps secure, universal access to integrated voice, video and data communications. Electronic Data Systems won the contract in October 2000. However, technical difficulties, deployment delays and user complaints have hampered the program since its inception.
Discovered on Aug. 19, SoBig.F is spreading today at a fast rate in the wild. The worm spreads via random e-mails. Garbage characters are appended to the SoBig worm in an attempt to make it difficult to detect, said Ken Dunham, malicious code intelligence manager at iDefense.
"SoBig.F shows how the spreading of malicious code has become more calculated and precise in recent months," Dunham said. "Malicious code actors are now releasing multiple variants of code sequentially using multiple techniques to help malicious code spread in the wild."
Attachments for SoBig.F known to date include files named details.pif, thank-you.pif, movie0045.pif, your-details.pif and application.pif. "Block all PIF files at the gateway level to help lower the risk of a SoBig worm outbreak," Dunham advised.
In addition, Symantec Security Response upgraded the Blaster variant known as W32.Welchia.Worm, Blast.D and Nachi to a Level 4 threat rating, with Level 5 being the highest.
Symantec upgraded the threat due to the nature of the worm and its effect on corporate enterprise networks. The worm exploits two vulnerabilities, Microsoft DCOM RPC vulnerability (described in Microsoft Security Bulletin MS03-026) using TCP Port 135, and Microsoft WebDav vulnerability (described in Microsoft Security Bulletin MS03-007) using TCP Port 80.
The worm attempts to download the DCOM RPC vulnerability patch from Microsoft's update site and then reboots the infected computer so the update can be installed. However, "once a system is infected, the worm aggressively searches for other machines to infect," according to the Symantec warning. "This results in an increase in traffic that impacts the network performance."