The huge cache of files recently leaked from Italian surveillance software maker Hacking Team is the gift that keeps on giving for attackers. Researchers sifting through the data found a new exploit for a previously unknown vulnerability in Adobe's Flash Player.
This is the second Flash Player zero-day exploit discovered among the files and the third overall -- researchers also found a zero-day exploit for a vulnerability in Windows.
A zero-day exploit is a previously unknown vulnerability for which a patch does not exist.
The first Flash Player exploit was identified Tuesday, less than two days after a hacker dumped on the Internet over 400GB worth of files, email communications, business documents, source code and other internal data from the Milan-based company that sells computer surveillance and intrusion tools to government agencies around the world.
The exploit was quickly adopted by cybercriminals and was integrated into commercial exploit kits before Adobe released a patch for it. Exploit kits are malicious tools used in large-scale attacks launched through compromised websites or malicious advertisements.
Adobe patched the vulnerability targeted by the exploit on Wednesday, but attackers are still using it. A well known cyberespionage group known as Wekby actually sent emails to companies advising them about the Adobe patch, but linking to the exploit instead, security vendor Volexity reported.
The new Flash Player exploit, which takes advantage of an yet-to-be-patched vulnerability, was identified among the Hacking Team files by researchers from security vendor FireEye. Adobe confirmed the vulnerability Friday and said that it plans to patch it next week. The flaw is being tracked as CVE-2015-5122 in the Common Vulnerabilities and Exposures database.
According to researchers from Trend Micro, the new exploit affects the latest versions of Flash Player on Windows, Mac and Linux and can be easily adapted to execute a malicious payload, like a malware program.
These exploits were likely provided by Hacking Team to its customers so they can deploy Remote Control System (RCS), the company's powerful spyware, on the computers of users targeted for surveillance. The exploits allow malware to be silently installed when users visit a website, an attack technique known as a drive-by download.
It's not clear if these two Flash Player exploits were developed by Hacking Team's employees or if they were acquired from third-parties. Leaked emails from Hacking Team reveal that the company was buying exploits through brokers and from individual researchers, but that it also had an internal research team for developing such attack tools.
The revelations are likely to fuel the debate about the zero-day exploit market and whether it's ethical for government agencies to contribute to Internet insecurity by creating the incentive for private companies and security researchers to stockpile critical flaws for profit instead of reporting them to affected vendors.
In May, the U.S. Commerce Department proposed changes to an international arms control pact called the Wassenaar Arrangement that would enforce export controls for software exploits and other computer intrusion software. The proposed changes are open to a two-month comment period.