A newly observed campaign leveraging the RIG exploit kit is targeting outdated versions of popular applications such as Flash, Internet Explorer, or Microsoft Edge to distribute the Cerber ransomware, Heimdal Security warns.
The attack leverages a swarm of malicious domains to launch drive-by attacks against unsuspecting visitors and preys on their failure to update applications in a timely manner. Thus, as long as they use outdated browsers or plugins that contain known vulnerabilities, they are likely to be infected with malware when navigating to one of those sites.
As part of the attack, cybercriminals compromise websites to inject malicious scripts that don’t even require user interaction for a successful infection: when the user navigates to the infected site, the attack is triggered. However, only outdated versions of Flash Player, Silverlight, Internet Explorer and Microsoft Edge are targeted in this attack, Heimdal Security reports.
According to Heimdal Security, RIG attempts to exploit one of 8 vulnerabilities in the aforementioned products, including CVE-2015-8651 (CVSS Score: 9.1), CVE-2015-5122 (CVSS Score: 10, affects nearly 100 Flash versions), CVE-2016-4117 (CVSS Score: 10), CVE-2016-1019 (CVSS Score: 10), CVE-2016-7200 and CVE-2016-7201 (both CVSS Score: 7.6, affecting Microsoft Edge), CVE-2016-3298 (CVSS Score: 3.6, affects Internet Explorer versions 9, 10, 11), and CVE-2016-0034 (CVSS Score: 9.3).
After successfully compromising user’s computer, the exploit kit proceeds to downloading and installing the Cerber ransomware, one of the most prolific threats last year. The malware was designed to encrypt user’s files and demand a ransom for the decryption key.
The RIG exploit kit variant spotted in this campaign is the Empire Pack version (RIG-E), while the abused domains are part of the so-called Pseudo-Darkleech gateway, researchers say. The gate was seen dropping Cerber last month as well. Previously, it was used to distribute other types of ransomware.
According to Heimdal Security researchers, the one thing that users must do to ensure increased protection is to keep their software updated at all times. Long said to be essential to good security, applying security updates in a timely manner is at the heart of prevention when it comes to exploit kit attacks.
“As you can see, cybercriminals often use vulnerabilities already patched by the software developer in their attacks, because they know that most users fail to apply updates when they’re released. In spite of the wave of attacks, many Internet users still choose to ignore updates, but we hope that alerts such as this one will change their mind and make them more aware of the key security layer that updates represent,” Heimdal’s security evangelist Andra Zaharia notes.