Denial of service attacks used to cover up fraudulent bank transfers

Brian Krebs documents a sophisticated offline/online attack on banks. Thieves combine a fraudulent wire-transfer to an innocent jewelry store with a denial-of-service attack on the bank that ties up the IT and other staff. The jeweler has been told that the money is to buy expensive jewels and watches, which are given to a stooge recruited as a courier and reshipper.

The bureau says the attacks coincide with corporate account takeovers perpetrated by thieves who are using a modified version of the ZeuS Trojan called "Gameover." The rash of thefts come after a series of heavy spam campaigns aimed at deploying the malware, which arrives disguised as an email from the National Automated Clearing House Association (NACHA), a not-for-profit group that develops operating rules for organizations that handle electronic payments. The ZeuS variant steals passwords and gives attackers direct access to the victim's PC and network.

In several recent attacks, as soon as thieves wired money out of a victim organization's account, the victim's public-facing Internet address was targeted by a network attack, leaving employees at the organization unable to browse the Web.

A few of the attacks have included an odd twist that appears to indicate the perpetrators are using money mules in the United States for at least a portion of the heists. According to an FBI advisory, some of the unauthorized wire transfers from victim organizations have been transmitted directly to high-end jewelry stores, "wherein the money mule comes to the actual store to pick up his $100K in jewels (or whatever dollar amount was wired)."

DDoS Attacks Spell 'Gameover' for Banks, Victims in Cyber Heists