Point-of-sale (PoS) systems at major retailers, hotel chains and restaurants worldwide have been hit by new custom malware that targets the PoS.

Researchers at Seculert, who discovered the so-called "Dexter" malware, won't name names of the companies with the 200 to 300 active attacks against their PoS systems across 40 countries. Remote malware attacks against PoS systems aren't new, but most PoSes fall victim to physical skimming attacks, where the bad guys rig the devices with sniffers that steal debit- and credit-card information onsite at the stores or other payment machines.

Barnes & Noble was the most recent high-profile retailer to get owned by a PIN-pad scam.