Recently breached surveillance software maker Hacking Team had access to three different exploits for previously unknown vulnerabilities in Flash Player. All of them are now out in the open, putting Internet users at risk.
Milan-based Hacking Team develops and sells surveillance software to government agencies from around the world. On July 5, a hacker released over 400GB of data stolen from the company on the Internet, including email communications, business documents, source code and other internal files.
On Tuesday, researchers found a proof-of-concept exploit among Hacking Team's files that worked against the latest version of Flash Player. Cybercriminals were quick to adopt it and were already using it in large-scale attacks by the time Adobe Systems released a patch for it on Wednesday.
This was followed up Saturday by researchers from Trend Micro with yet another find, putting the number of Flash Player zero-day exploits used by Hacking Team to three -- at least so far.
Only one of the vulnerabilities targeted by those exploits has been patched so far, with Adobe planning to release fixes for the other two -- CVE-2015-5122 and CVE-2015-5123 -- later this week.
That's a problem because the cybercriminals behind the Angler Exploit Kit were already using the exploit discovered by FireEye (CVE-2015-5122) by Sunday. The malicious activity was spotted by a malware researcher known online as Kafeine who specializes in tracking drive-by download attacks.
It's very likely that attackers are also working on integrating the exploit found by Trend Micro (CVE-2015-5123) in commercial exploit kits, if they haven't already.
"Until an update is available, users should consider disabling Adobe Flash," researchers from Trend Micro said in a blog post. "Extra caution should be exercised for the foreseeable future and special attention paid for the possibility of compromised ad servers."
Web-based exploits are typically used to infect computers when users visit legitimate websites that were compromised or when their browsers load malicious advertisements.