Computers infected with a well-known virus began downloading a new spam tool Sunday night used by hackers to send unwanted e-mail.Virus writers who are part of the infamous Bagle spam gang began sending a new spamming tool Sunday night to thousands of hacked computers, said Mikko Hypponen, chief research officer for F-Secure, a security company based in Helsinki. If a computer is infected with the Bagle virus, a hacker can download other malicious programs to the machine. In turn, those programs can send out spam to other machines without the knowledge of the user.Once a computer is under their control, virus writers can upgrade the malicious software they have installed. Sunday night, machines infected with Bagle variants were downloading the new spam tool from a server in Slovakia hosting a real estate website.“This is the way virus writers can upgrade the infected machines,” Hypponen said. “It’s like [Microsoft’s] Windows update for viruses.”The download link was buried within the website, and it’s unlikely the owners had any idea it was being used. Sunday night, the link was cut off, Hypponen said.But within hours, a French site hosted in the United States was hosting a link with the malware, Hypponen said. The ISP hosting that site has been contacted, but so far the link remains active, he said.F-Secure uses automated tools to poll URLs used by virus writers to host bad malware, Hypponen said.About 99 percent are decoys, set up to throw off attempts to track them down. But when a site suddenly becomes active, Hypponen said, efforts are made to contact ISPs to shut them down.— Jeremy Kirk, IDG News ServiceFor related news coverage, read FTC, Prosecutor Shutter Calif. Spam Operation and New Generation of IE Malware Now Circulating.Keep checking in at our CSO Security Feed page for updated news coverage. Related content news UK government plans 2,500 new tech recruits by 2025 with focus on cybersecurity New apprenticeships and talent programmes will support recruitment for in-demand roles such as cybersecurity technologists and software developers By Michael Hill Sep 29, 2023 4 mins Education Industry Education Industry Education Industry news UK data regulator orders end to spreadsheet FOI requests after serious data breaches The Information Commissioner’s Office says alternative approaches should be used to publish freedom of information data to mitigate risks to personal information By Michael Hill Sep 29, 2023 3 mins Government Cybercrime Data and Information Security feature Cybersecurity startups to watch for in 2023 These startups are jumping in where most established security vendors have yet to go. By CSO Staff Sep 29, 2023 19 mins CSO and CISO Security news analysis Companies are already feeling the pressure from upcoming US SEC cyber rules New Securities and Exchange Commission cyber incident reporting rules don't kick in until December, but experts say they highlight the need for greater collaboration between CISOs and the C-suite By Cynthia Brumfield Sep 28, 2023 6 mins Regulation Data Breach Financial Services Industry Podcasts Videos Resources Events SUBSCRIBE TO OUR NEWSLETTER From our editors straight to your inbox Get started by entering your email address below. Please enter a valid email address Subscribe