The Gumblar virus's ability to get malware onto a user's PC is only the tip of the iceberg, according to one spokesperson.
Tom Newton, product manager at security specialist SmoothWall, claimed that the biggest threat of the Gumblar infection is becoming a malware host rather than compromised PCs.
Newton said: “For many businesses the web is their shop window. If their website becomes a malware host, it could cause massive damage to their online profile. Not only are they likely to be blacklisted by public-spirited search engines and other filtering systems, but their reputation may suffer as people work out where and how they were infected.
“Small and medium businesses are more likely to suffer these attacks than any other: those with sites with sufficient visibility and insufficient security. Some reports suggest that compromised FTP passwords were to blame for many of the infected sites.
“From experience though, I would suggest that these clever guys will have more than one way to crack that nut. Forum software and content management systems are prime targets: easily spotted and usually helpfully accompanied by a version number. If there are known exploits you are extremely vulnerable.”
He recommended webmasters to stop using FTP, to ask the web host if there is a more secure alternative, such as SFTP for example, to keep the CMS or forum software up to date and be aware of new vulnerabilities. He also claimed that as many site components have default passwords, to keep on top of them and do not save them unless they are encrypted.