Adobe on Wednesday released security updates for critical vulnerabilities in Adobe Illustrator CS4 (14.0.0) and Adobe Illustrator CS3 (13.0.3 and earlier versions) for Windows and Mac OS X.

The company also said that on January 12 it will release security updates for Adobe Reader 9.2 and Acrobat 9.2, and Adobe Reader 8.1.7 and Acrobat 8.1.7 for Windows and Macintosh, and Adobe Reader 9.2 for UNIX, to resolve a critical vulnerability that is being actively exploited.

Adobe first acknowledged the vulnerability in its Acrobat Reader and Acrobat software on December 15.

The vulnerabilities in Illustrator have been known since December 3.

Adobe warns that these vulnerabilities could be used to execute arbitrary code on affected computers or to cause a crash.

Commenting on malware Symantec detected last month that attempts to exploit the Acrobat vulnerability, security researcher Mircea Ciubotariu said, "[T]his particular exploit seems to be stealthier than other Acrobat exploits we have seen, in the sense that it won't restart the whole application, thus not raising user's suspicion that something may have gone wrong."

"This is the work of a skilled programmer, not some script kiddie who found a proof of concept on an exploit site," Ciubotariu added.

On Sunday, SANS Internet Storm Center Analyst Bojan Zdrnja also found evidence of professionalism in his analysis of exploit code, an observation that should serve as a reminder of the risks posed by PDFs from unknown parties.

"If we are to judge the new year by sophistication the attackers started using, it does not look too good," he wrote in a blog post.