Cybersecurity researchers have discovered a new zero-day vulnerability in Adobe Flash Player that hackers are actively exploiting in the wild as part of a targeted campaign appears to be attacking a Russian state health care institution.
The vulnerability, tracked as CVE-2018-15982, is a use-after-free flaw resides in Flash Player that, if exploited successfully, allows an attacker to execute arbitrary code on the targeted computer and eventually gain full control over the system.
The newly discovered Flash Player zero-day exploit was spotted last week by researchers inside malicious Microsoft Office documents, which were submitted to online multi-engine malware scanning service VirusTotal from a Ukrainian IP address.
The maliciously crafted Microsoft Office documents contain an embedded Flash Active X control in its header that renders when the targeted user opens it, causing exploitation of the reported Flash player vulnerability.
According to cybersecurity researchers, neither the Microsoft Office file (22.docx) nor the Flash exploit (inside it) itself contain the final payload to take control over the system.
Instead, the final payload is hiding inside an image file (scan042.jpg), which is itself an archive file, that has been packed along with the Microsoft Office file inside a parent WinRAR archive which is then distributed through spear-phishing emails, as shown in the video below: