Botnet Exploits PDF Flaw

The Zeus botnet is now using an unpatched flaw in Adobe's PDF document format to infect users with malicious code, security researchers said.
The attacks come less than a week after other experts predicted that hackers would soon exploit the "/Launch" design flaw in PDF documents to install malware on unsuspecting users' computers.

The just-spotted Zeus variant uses a malicious PDF file that embeds the attack code in the document, said Dan
Hubbard, CTO of San Diego, California-based security company Websense. When users open the rogue PDF, they're asked to save a PDF file called "Royal_Mail_Delivery_Notice.pdf." That file, however, is actually a Windows executable that when it runs, hijacks the PC.

Zeus is the first major botnet to exploit a PDF's /Launch feature, which is, strictly speaking, not a security vulnerability but actually a by-design function of Adobe's specification. Earlier this month, Belgium researcher Didier Stevens demonstrated how a multistage attack using /Launch could successfully exploit a fully-patched copy of Adobe Reader or Acrobat.