For instance, “like’’ buttons can be “clickjacked,’’ security specialists say, so that when a user clicks on them an invisible code or software script is activated. Sometimes they are directed to websites peddling malware disguised as antivirus software. Once the stealth software is inadvertently downloaded, it can damage a computer, network, or program, sometimes by unleashing a virus.
Not so long ago, it was relatively easy to avoid Internet scams if you refrained from doing “dodgy things on the Net,’’ said Chester Wisniewski, a senior adviser with Sophos. Today’s security challenges are more formidable, he said, because “so many legitimate things are infected.’’