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.
The Year in Web Threats: Web Skimmers Take Advantage of Cloud Hosting and More
Unit 42 analyzed 2.24 million web threat incidents, finding web skimmers increasingly hosted on cloud infrastructure to steal payment card data.
Palo Alto Unit 42 analyzed 2,241,354 web threat incidents and 831,550 unique URLs detected via Advanced URL Filtering between October 2020 and September 2021. Threat activity peaked from October 2020 to January 2021, coinciding with the holiday shopping season, with most malicious domains geolocated to the United States, Russia, and Germany. Web skimmers ranked third among the top five threat classes and showed the most code diversity, making detection harder. Researchers observed more web skimmer families being hosted on cloud platforms to steal payment data and PII.
Almost Half of Malware Samples Communicate Direct to IP
Unit 42 analysis of 4 million malware reports finds 45% of C2-active samples connect directly to hard-coded IPs, bypassing DNS defenses.
Palo Alto Unit 42 analyzed over 4 million Advanced WildFire dynamic analysis reports and found that 45.32% of malware samples with C2 activity made at least one direct-to-IP connection, accounting for 23.17% of all C2 connection attempts. The firm proposes zero trust IP (ZT-IP), an enforcement approach that verifies whether outbound destinations were ever sanctioned by a DNS response. ZT-IP analysis surfaced Phorpiex ransomware droppers fetching payloads directly from C2 IPs, a persistent data exfiltration campaign using an obfuscated \GET protocol, and Mozi P2P botnet payloads delivered to IoT devices without DNS. Only 1% of benign samples connected directly to untrusted IP addresses.
Trends in Web Threats: Old Web Skimmer Still Active Today
Unit 42 detected 577,000 landing URL incidents in Q1 2022, with an old web skimmer family still actively stealing payment card data.
Palo Alto Unit 42 detected 577,275 landing URL incidents (116,643 unique) and 2,043,862 malicious host URL incidents (180,370 unique) between January and March 2022. Web threat volumes declined after the November 2021 holiday peak, but an old web skimmer family remained active. Business and economy sites overtook personal sites as the most common apparently benign entry points. Most malicious domains geolocated to the United States, Germany, and Russia, though proxy servers and VPNs obscure true locations.