BlacoleRef is a type of malware which uses your Internet browser to attack your computer and infect it with other malware, such as trojans and viruses. It belongs to the Blacole family of malware, which together are known as the Blacole (or "Blackhole") exploit kit. 

Blacole attacks your computer by exploiting multiple vulnerabilities through your Internet browser.

A vulnerability is like a "hole" in your software that malware can use (or "exploit") to get on your computer. These vulnerabilities, or holes, are fixed by installing updates to the software; this is why it is extremely important to keep all of the programs on your computer up to date. See here for information on how to update some software.

Typically, the Blacole exploit kit attempts to exploit vulnerabilities in applications such as Oracle Java, Sun Java, Adobe Acrobat and Adobe Reader.

For more information on this exploit kit, and for steps you can take to avoid your computer from being infected, please see the detailed Blacole description.

Install updates to prevent infection

The nature of this threat means that you may need to take some steps to prevent being vulnerable from this, and similar exploits.

Download updates for Adobe products from the following link:

• Updating Software

1. Clear the Java cache
2. Update Java
3. Remove older versions of Java

Note: This detection may be triggered when you visit a website that contains the malicious code. Even if you are not using a vulnerable version of the JRE this detection may be reported when you visit a website that contains the malicious code. This does not mean that you have been compromised, rather that an attempt to compromise your computer has been made.

For detailed information about these steps, please see the Additional removal instructions below.

There are no common symptoms associated with this threat - links are activated within IFrames while viewing web content on maliciously modified pages. Alert notifications from installed antivirus software may be the only symptoms.

Installation

Your antivirus software may detect BlacoleRef when you visit a compromised or malicious webpage. A compromised webpage is one in which an attacker has inserted malicious JavaScript code without the webpage owner's knowledge.

When you visit the webpage, the JavaScript code - detected as BlacoleRef - is run.

Payload

Exploits vulnerable webpages

BlacoleRef family is designed to load a hidden IFrame that contacts a malicious page that is stored on a web server. This page determines information about your browser, such as what browser it is (for example, Internet Explorer or Firefox), what version it is, and what plugins or extensions you have installed.

The page then redirects the hidden IFrame to another page (or multiple pages) that specifically uses or "exploits" only those vulnerabilities that your browser is susceptible to. These vulnerabilities are then used to download malware onto your computer.

In this way, BlacoleRef forms part of a larger process, all of which is designed to have the greatest success of infecting your computer with malware.

Additional information

This threat's payload may vary, depending on what the server is distributing at any one time.

A common payload is to download additional malware onto your computer, such as trojans and viruses. It could also download malware that then downloads or drops other malware (these are known as trojan downloaders and droppers) or malware that allows remote attackers to gain access and control to your computer (these are known as backdoor trojans).

Further reading

Get gamed and rue the day...

Analysis by Methusela Cebrian Ferrer

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

• Microsoft Security Essentials or, for Windows 8, Windows Defender
• Microsoft Safety Scanner

Additional removal instructions

A detection of this exploit may be triggered from your Java cache, if a previous attempt at exploit has been made. When using Java, the Java cache is known as the Temporary Files folder and is commonly located at C:\Users\<user name>\AppData\Local\Sun\Java\Deployment\cache\. The Temporary Files (or cache) folder contains webpage content that is stored on your hard disk for quick viewing.

We recommend that you delete your temporary Java files to prevent the persistent detection of this exploit from within this folder. For instructions on how to delete temporary Java files, please see the following article:

How do I clear the Java cache?

Update vulnerable Java applications

This threat exploits a known vulnerability in Java. After removing this threat, make sure that you install the updates available from the vendor. You can read more about this vulnerability in Java, as well as where to download the software update from the following links:

• CVE-2013-0422
• Java Download

It may be necessary to remove older versions of Java that are still present. Keeping old and unsupported versions of Java on your system presents a serious security risk. To read more about why you should remove older versions of Java, see the following information.

• Remove older versions of Java