Kaspersky Lab researchers have automatically detected a new exploited vulnerability in the Microsoft Windows OS kernel, the third consecutive zero-day exploit to be discovered in three months.

The latest exploited vulnerability (CVE-2018-8611) was found in malware targeting a small number of victims in the Middle East and Asia.

Because the vulnerability exists in the kernel mode module of the operating system, the exploit is particularly dangerous and can be used to bypass built-in exploit mitigation mechanisms in modern web browsers, including Chrome and Edge.

The vulnerability has been reported to Microsoft, and a patch has been released.

Zero-day vulnerabilities are previously unknown, and therefore unpatched, software bugs that attackers can exploit to gain access to victim systems and devices. They are immensely valuable to threat actors, and difficult to detect.

All three exploits were detected by Kaspersky Lab’s Automatic Exploit Prevention technology, embedded in most of the company’s products. Like the previous two exploited vulnerabilities (CVE-2018-8589 and CVE-2018-8453), patched by Microsoft in October and November respectively, the latest exploit was found used in-the-wild targeting victims in the Middle East and Africa.

The exploit for CVE-2018-8589 was called “Alice” by the malware writers, who also referred to the latest exploit as “Jasmine”. Kaspersky Lab researchers believe that the new vulnerability has been exploited by multiple threat actors, including a new advanced persistent threat (APT) called Sandcat.

“The detection of three kernel mode zero-days within a few months is evidence that our products use the best technologies, which are capable of detecting such sophisticated threats. For organisations, it is important to understand that to protect their perimeter they should use a combined solution, like endpoint protection with an advanced threat detection platform,” saysAnton Ivanov, a security expert at Kaspersky Lab.