"At the AusCERT conference this week, you may have collected a complimentary USB key from the IBM booth," IBM's chief technologist in Australia, Glenn Wightwick, wrote to attendees. "Unfortunately we have discovered that some of these USB keys contained malware and we suspect that all USB keys may be affected."
It warned recipients to not use the drives, and requested their return to a postage-free address.
IBM didn't name the malware in question, noting only that it "is contained in the setup.exe and "autorun.ini" files, had been around since at least 2008, and could be detected "by the majority of antivirus products" on the market.
It warned that the malware would automatically run, and advised anyone who had actually plugged in the offending thumb drive to "contact your IT administrator for assessment, remediation and removal."
According to Graham Cluley at Sophos, the drives contained two different pieces of malware: The setup file is known as LibHack-A, and refers to "often otherwise legitimate applications that have been altered to load a malicious library file with a .dat extension," said Cluley on the Sophos blog. Thankfully, a crucial component is missing, which means it doesn't work.
But that's not true for the other piece of malware, a keystroke-monitoring Windows worm known as Agent-FWF. "Hardly the kind of code a security researcher would want running on their computer," said Cluley.
What can other companies do to ensure that their USB thumb drives aren't delivering hidden extras to conference-goers and potential customers? For starters, while auto-run features may seem mandatory to ensure that thumb-drive recipients receive your marketing message, avoid them.
"Auto-run files seem like a good idea because they force the user to view your pre-loaded information but you do, as IBM have discovered, run a very small risk with auto-run files of introducing malware," Phil Battison, director at memory stick vendor USB2U, said in a statement. Better, he said, to stick to just data files, such as Word documents, Excel spreadsheets, PowerPoint decks, or PDFs.