The attack group known as APT3 is now using exploits for recently-patched Windows vulnerabilities, according to a report from FireEye.
APT3 is believed to be behind ‘Operation Clandestine Fox’, a campaign first disclosed in April when the group began using a zero-day in Internet Explorer in targeted attacks. In May, the attackers began specifically targeting Windows XP machines running Internet Explorer 8. The group has also been seen using social networks to fool targets into installing malware.
“APT3…the actors responsible for Operation Clandestine Fox has quietly continued to send waves of spearphishing messages over the past few months,” FireEye researchers blogged. “This actor initiated their most recent campaign on November 19, 2014 targeting multiple organizations. The attacker leveraged multiple exploits, targeting both CVE-2014-6332 and CVE-2014-4113. CVE-2014-6332 was disclosed publicly on 2014-11-11 and is a Windows OLE Automation Array Remote Code Execution vulnerability. CVE-2014-4113 is a privilege escalation vulnerability that was disclosed publicly on 2014-10-14.”
“The use of CVE-2014-6332 is notable, as it demonstrates that multiple classes of actors, both criminal and APT alike, have now incorporated this exploit into their toolkits,” the researchers continued. “Further, the use of both of these two known vulnerabilities in tandem is notable for APT3. This actor is historically known for leveraging zero-day vulnerabilities in widespread but infrequent phishing campaigns. The use of known exploits and more frequent attacks may indicate both a shift in strategy and operational tempo for this group.”
CVE-2014-6332 was fixed earlier this month during Patch Tuesday. The bug garnered significant attention because it had exploitable for nearly two decades. The vulnerability affected all versions of Windows from Windows 95 on, and has been remotely exploitable since Internet Explorer 3.0.
CVE-2014-4113 meanwhile exists when the Windows kernel-mode driver improperly handles objects in memory. An attacker who exploited it could potentially run arbitrary code in kernel mode.
“Although APT3 is well known for employing zero-day exploits in their attacks, recent activity has demonstrated that they will also attack targets with known exploits or social engineering,” the FireEye researchers wrote. “Since Operation Clandestine Fox, we have observed this actor execute multiple attacks that did not rely on zero-day exploits. The combination of this sustained operational tempo and lack of zero-day exploits may indicate that this group has changed strategy and has decided to attack more frequently and does not have steady access to zero-day exploit code.”
“No matter the strategy, this actor has shown an ability to operate successfully,” the researchers added.