Understanding Angler Exploit Kit
Unit 42 explains exploit kit fundamentals, describing how landing pages profile victims, deliver exploits, and install malware payloads on Windows hosts.
Unit 42 published a primer on exploit kit fundamentals, defining vulnerabilities, exploits, malware payloads, actors, and campaigns in EK-based attacks. It explains the infection chain: a landing page profiles the victim's Windows system for vulnerable applications such as Flash Player, Java, Silverlight, and Internet Explorer, then a matching exploit executes a downloader or final payload, often delivered encrypted with XOR or RC4. The post also describes the EK-as-a-Service business model, in which leading EKs are rented for a few thousand dollars per month while buyers supply campaign infrastructure.
Another Apache Log4j Vulnerability Is Actively Exploited in the Wild (CVE-2021
Apache Log4j 2 RCE CVE-2021-44228 is actively exploited via crafted JNDI lookups; Palo Alto Unit 42 urges upgrading to Log4j 2.17.1.
Unit 42 details CVE-2021-44228, an easily exploited remote code execution flaw in Apache Log4j 2 where attacker-supplied JNDI lookups in logged user input cause payload download and execution. Massive internet-wide scanning for unpatched systems has begun, with observed follow-on activity including information stealing, Cobalt Strike delivery, and coinmining. The recommended fix is Log4j 2.17.1, which also patches CVE-2021-45046, CVE-2021-45105, and CVE-2021-44832. Widely used Java software including Apache Struts, Solr, Druid, Flink, ElasticSearch, and Spring Boot is affected.