Exploit:JS/Anglerek

An exploit kit is a toolkit that can probe for and run exploit code that targets vulnerabilities in an accessible device in order to gain further access or to drop additional malware onto the compromised device.

Angler is one of the most common exploit kits found in-the-wild today.

Finding victims to exploit

To find victims, attackers can insert the Angler EK onto compromised legitimate sites, for example by hacking into the site and hosting the kit on a page, or by hiding it in an ad and slipping it into an ad-serving network that leads to the malicious ad being displayed on a website (this is a form of malvertising).

Attackers can also host the EK on a webpage under their own control, and then hijack or redirect web traffic to force users to visit the malicious page, where their devices can be are exposed to the exploit kit's probing.

Exploiting unpatched vulnerabilities

Once a user (or more accurately, their computer or mobile device) is brought into contact with an exploit kit, it will seek out and try to exploit specific vulnerabilities. The exploit code used by the Angler kit will only work if the user's device has unpatched vulnerabilities in the operating system or specific installed programs - most commonly, popular programs such as Flash Player, Java or Internet Explorer.

Attackers can also update the exploit code used in an EK so that it can target any newly announced vulnerabilities.

Because exploit kits are only able to impact devices that have unpatched vulnerabilities, users are strongly advised to promptly apply the latest security updates for any installed programs, and their device's operating system, whenever they are available.

For more about exploit kits, see Article: Exploit Kits.