According to antivirus firm Symantec, the Linux.Slapper.Worm is the first worm to make use of peer-to-peer networking technology, which has allowed infected servers to maintain contact. This would potentially give a hacker control of a constellation of infected boxes.
The worm, which is still being analyzed, can capture e-mail addresses and could potentially do greater harm, says Oliver Friedrichs, senior manager at the Symantec Security response division. Symantec said that on Friday there were at least 2,000 infections from the worm, which was first reported in Portugal and Romania.
The worm can infect Linux servers from companies such as Red Hat, Mandrake, Caldera, Slackware and Debian that have not been upgraded to the 0.9.6g version of the OpenSSL Group's software for Secure Sockets Layer. That upgrade fixes the vulnerabilities detailed on July 30.
The worm is raising particular concern because "it has its own peer-to-peer networking protocol," said Friedrichs. "Potentially, someone can inject a command into the peer-to-peer network and send it to the compromised hosts."
Symantec is still examining the Linux.Slapper.Worm to better understand how dangerous it is. The worm spreads like the well-known Nimda worm, which started a year ago, by scanning. That scanning activity might result in some denial-of-service problems.
But unlike Nimda, which is still active and infects vulnerable Microsoft Internet Information Servers, the Linux.Slapper.Worm is said to go one step further and set up links among the Linux machines it infects. Symantec said it intends to issue periodic updates on what it discovers about Linux.Slapper.Worm.