Adobe has confirmed reports that yet another unpatched vulnerability in the latest versions of its ubiquitous software is being actively exploited to infect end users with data-stealing malware.
The vulnerability exists in Adobe's Reader document viewer and Flash Media Player for Windows, OS X and Unix operating systems, Adobe warned on Thursday. According to independent researchers, it is being exploited in the wild against Reader for Windows to install a nasty trojan known as Wisp, which according to Microsoft, steals sensitive user data and installs a backdoor on compromised systems.
The vulnerability itself resides in Adobe's Flash Player, which is available as stand alone software and is also embedded into Reader. According to researcher Mila Parkour of the Contagio Malware Dump blog, poisoned PDF documents are circulating that drop two malicious binaries onto Windows machines that open the document files.
A screenshot identified the two files as nsunday.exe and nsunday.dll. A Virus Total scan showed just 15 of 42 antivirus programs were detecting the malicious EXE. She didn't say whether the attacks succeed against more recent versions of the OS, which Microsoft has designed to withstand many of the most common types of exploits.
Adobe said it planned to patch the vulnerability in Flash during the week of November 9 and in Reader during the week of November 15. The schedule is puzzling, since Reader has been confirmed to be under attack and Flash has not been confirmed.
In the meantime, users can protect themselves by using an alternate document viewer, such as Foxit. For those who must use Reader, Adobe said they can mitigate attacks by removing functionality known as AuthPlay, by following the instructions near the bottom of this advisory. Adobe provided no temporary measures Flash users can follow.
It's been a bad couple of years for Adobe's security team, which has gotten repeatedly hammered by critical vulnerabilities that are exploited by criminals to install malware on users' machines. Three weeks ago, the company issued a fix for a security flaw in Reader that was also under attack by a highly sophisticated exploit. Last month, Adobe fixed a critical vulnerability in Flash that was also being used to compromise end user computers.
Adobe is also in the process of developing a patch for a code-execution bug in its Shockwave Player.
By many researchers' reckoning, Reader is among the world's most exploited applications, in close competition with Oracle's Java framework and, of course, various Microsoft programs.
The company is close to rolling out a security sandbox for Reader that's designed to lessen the effects of attacks by separating the application from core parts of the OS. Given the steady stream of in-the-wild exploits, it can't come soon enough. ®