Security researchers have confirmed how a 9.8 severity vulnerability was used in a zero-click cyber attack chain by Russian hackers against Windows users.

The Russia-aligned RomCom gang exploited the vulnerabilities to target hundreds of Firefox users across Europe and North America.

Russian hacking group RomCom are taking advantage of vulnerabilities found in Windows and Mozilla products to silently install malware.

Further investigation led to the discovery of a second vulnerability, this time in Windows, tracked as CVE-2024-49039, WHICH allows previously authenticated crooks to run arbitrary code in the system. By chaining the two vulnerabilities together, the attackers were able to deploy backdoors on target devices.

Russian-based RomCom cybercrime group chained two zero-day vulnerabilities in recent attacks targeting Firefox and Tor Browser users across Europe and North America.

The no-click exploit launched in October infected computers in Europe and North America with the RomCom backdoor when victims were redirected through attacker-controlled websites.

ESET Research details the analysis of a previously unknown vulnerability in Mozilla products exploited in the wild and another previously unknown Microsoft Windows vulnerability, combined in a zero-click exploit.