Pictures, PowerPoint slides, PDFs, even innocuous ads on legitimate sites can carry malware that will install itself on your PC by exploiting flaws in the browser you use. Undetected by anti-virus software, robot software can piggy-back on bank transactions, avoid anti-fraud detections systems, and send money to "mule" accounts operated by criminals in Eastern Europe. That's exactly what happened to 3,000 bank customers when online thieves stole $1 million dollars before they were caught last July by M86, a networking security firm.
Unsuspecting customers visited legitimate-looking websites to download, say, a screen saver. Others received an email with pictures of cute animals or a PowerPoint presentation with a patriotic theme and, responding to heartfelt exhortations to forward it or risk a lifetime of bad luck, they obediently sent it to friends.
