Ransomware rears ugly head, demands $120 to unlock files
Online extortionists return in a pair of campaigns, say security pros
Computerworld - Ransomware is making a comeback, plaguing users with extortion demands of up to $120 to return documents or drives to their control, security experts said today.
There appear to be two different campaigns underway, said Chet Wisniewski, a senior security adviser at antivirus vendor Sophos.
'It looks like we're looking at different samples,' said Wisniewski, referring to analyses done by Sophos and other security firms, including Kaspersky Lab and CA.
Last week, Sophos came across malware that used malicious PDF documents to exploit one or more since-patched vulnerabilities in Adobe Reader. If successful, the malware sniffed out a wide range of file formats -- including numerous media formats, Microsoft Office and OpenOffice.org document formats and image formats -- then partially encrypted those files to make then unreadable.
Other security companies have reported seeing the same ransomware, the term used to describe a scheme where hackers plant malware that encrypts files and then displays a message demanding money to unlock the data.
Unlike the previous variants, it doesn't delete files after encryption," wrote Kaspersky researcher Vitaly Kamluk on the company's blog. "Instead, it overwrites data in the files, which makes it impossible to use data-recovery software such as PhotoRec, which we suggested during the last attack."
U.S.-based CA reported Tuesday on a different kind of ransomware that tried to infect the master boot record, or MBR, of the hard drives of Windows machines, crippling them and making them unbootable.
Instead, an extortion note appears on the screen. "Your PC is blocked," the message reads. "Any attempt to restore the drive using other way will lead to inevitable data loss!!!:
The extortionists demand $100 for an unlocking key.
Users running the newest version of Adobe's Reader, which that company released two weeks ago, are safe from the PDF-borne malware, said Wisniewski. Reader X includes a "sandbox" designed to protect users from PDF attacks; Wisniewski confirmed that the sandbox stops the rogue PDF from infecting a Windows PC.
"And this is a great reason to do regular backups," Wisniewski added.
