Pierluigi Paganini November 09, 2012

We have had many opportunities recently to discuss about zero-day vulnerabilities, their knowledge is guarantee of success for the attackers and represents in many cases the certainty to not to be discovered.

The zero-day vulnerabilities are desirable for cybercrime that desires to find new ways to monetize cyber attacks, but also for state sponsored hackers that conduct cyber espionage operations or that hit a foreign government infrastructures.

The zero-day vulnerabilities are very dangerous both cases they impact critical systems or common use applications such as Windows OSs or Adobe products.

Abobe firm is one of the most attacked vendors due the large diffusion of its products, according the last Trend Micro Report “3Q 2012 SECURITY ROUNDUP” it is in the Top 10 vendors of Applications with most number of reported vulnerabilities.

At the end of September a group of hackers have signed malware using Adobe digital certificate obtained compromising a vulnerable build server that was used to get code validation from the company’s code-signing system.

The famous company has announced that it is investigating on possible critical security flaw previously unknown in the latest versions of its PDF Reader product.

What is worrying is the possibility that the zero-day could be sold in the underground marked kicking off an a series of cyber attacks.

Once again the discovery come from Russia, its a analysts are demonstrating great capabilities in investigations, the forensics firm Group-IB, the same that provided information on cybercrime activities in Russia in last months, has discovered the availability of a new exploit sold in the underground.

Personally, I appreciate the work of this company that is very attentive to the underground market and to dangers originating from it.

The exploit related to unknown vulnerability is sold approximately for 30 000 – 50 000 USD and is related to Adobe Reader version X and XI.

The situation appears paradoxal, Adobe recently introduced for the products compromised a security “sandbox” with the intent to block the exploitation of any previously unidentified security flaws.

What kind of attacks could be conducted with the exploit kit?

The zero-day vulnerability in Adobe X could be exploited to “execute its own shellcode with help of malformed PDF-documents with specially crafted forms.”

The post on the Group-IB website states:

“The vulnerability is also included in new modified version of “Blackhole Exploit-Kit”, which is used for the distributing the banking Trojans (Zeus, Spyeye, Carberp, Citadel) with the help of exploitation different vulnerabilities in client-side software.”

Andrey Komarov, the Head of International Projects Department of Group-IB: declared

«The vulnerability has some limitations, for example it could be successfully exploited only after the user will close the browser and restart it. Another variant is to organize interaction between the victim and the malformed PDF-document. Either way, the vulnerability is has very significant vector to be spread with bypassing of internal Adobe X sandbox, which is appealing for cybercrime gangs because in the past there was no documented method of how to bypass it with shellcode execution.».

The excellent blog KrebsonSecurity.com reported the response provided by Adobe reppresentative Wiebke Lips that declared:

“Adobe will reach out to Group-IB,”

“But without additional details, there is nothing we can do, unfortunately— beyond continuing to monitor the threat landscape and working with our partners in the security community, as always.”

Yesterday evening I had the opportunity to speak with Andrey Komarov, a person extremely helpful, who confirmed me that Group-IB has provided details to Adobe Product Security Incident Response Team (PSIRT).

Fortunately the distribution of malware is finite to a limited “circles of the underground.”

The POC of the zero-flaw found in Adobe X was published in YouTube by Group-IB US threat intelligence team:

Let’s think to the consequences to the inclusion of the exploit to the famous Black Hole exploit kit.

It could be a disaster!

Pierluigi Paganini