Home Malware Programs Potentially Unwanted Programs (PUPs) HanJuan Exploit Kit

HanJuan Exploit Kit

Posted: June 25, 2015

Threat Metric

Threat Level: 8/10
Infected PCs: 485
First Seen: June 25, 2015
Last Seen: August 28, 2022
OS(es) Affected: Windows

The HanJuan Exploit Kit is a Web-based threat that may install threatening software on your PC with exploits from other programs, such as your Web browser or Adobe's Flash platform. Recent campaigns involving the HanJuan Exploit Kit include attacks distributing banking Trojans and Trojan downloaders. Although limited samples of the HanJuan Exploit Kit are available, any exposure to this PC threat may risk compromising your PC's security, including data such as passwords. Anti-malware software can block a HanJuan Exploit Kit's attacks or remove its payload from your computer.

A Stealthy Exploit Kit Hits the Big-Time

Except for an attack involving Zero-Day (or unpatched) Flash Player vulnerabilities, the HanJuan Exploit Kit's previous history has included very limited incidents, leading to a limited sample size. However, a new campaign using the HanJuan Exploit Kit recently was confirmed for widespread distribution on the Ad.fly URL shortening service. Like its previous campaign, the Ad.fly attack used a compromised advertisement network for gaining access, followed by a chain of URL redirects eventually ending in exposure to the HanJuan Exploit Kit.

The HanJuan Exploit Kit, or HanJuan EK, loads exploits currently using vulnerabilities in Internet Explorer and Flash Player to initiate its attack that may install threats on your PC automatically. There are few or no visible signs for this attack's occurrence, which can be mitigated via blocking scripts.

The developers of the HanJuan Exploit Kit's current payloads have taken some steps to prevent malware experts from examining the Trojan, as well as blocking visible evidence of the program. The threat, identified as a variant of the minimalist Tinba Trojan (or Trojan.Agent.Fobber), injects its code into normal Windows components. It proceeds with monitoring all three Windows-favored browsers: Internet Explorer, Chrome and Firefox. So far, malware experts expect these attacks are implementing themselves with the purpose of collecting account logins and equally protected Web data.

How to Cut the Profits from Software-Exploiting Tactics

The HanJuan Exploit Kit differentiates itself from previous EKs due to its highly limited and specific usage. Despite being launched against random advertisement-viewing Web surfers, the HanJuan Exploit Kit's implementation clearly targets the most cost-efficient software platforms, with Windows owners being especially at risk. Its payloads also show clear signs of its developers being invested in the long-term security of their illicit endeavors, with multiple methods taken to obscure the threat from standard analytical techniques.

Regardless of its individual traits, the HanJuan Exploit Kit offers the same dangers to PC users as most other exploit kits. Updating all software and blocking scripted browser content (including Java, JavaScript, and Flash) by default are two steps that any PC user can take, free of charge, to protect their machines. Anti-malware products also can block attacks of a HanJuan Exploit Kit and other EKs, or remove their downloads after the fact.