Malware Prevention System

Overview

A malware prevention system (MPS), also known as a malware analysis appliance, can be an effective way to prevent malicious applications or scripts from landing and executing on a device. An MPS is installed at the network perimeter and needs to have a way to intercept binary files for inspection. One way is to have the MPS interface with an email gateway so that email attachments are stripped and fed to the MPS for inspection.

How it works

An MPS is focused on the application level of network activity and examines files employees download during the day. These files could be deliberately downloaded or accidentally, such as clicking the wrong link in an email. Regardless of the file or its delivery method, when downloaded, the MPS makes a copy of the file and executes (or detonates) it in a container that the MPS starts up to analyze the file. The analysis observes and records the actions that the file performs, such as:

• Network connections

• What’s loaded into memory

• Files that are accessed or changed

• Registry changes

• Processes it spawns

Based on the analysis and comparison with signatures of other known malicious files, the MPS forms a conclusion about whether the binary is malicious.

Only providing an alert on the first infection

It’s possible that the first infection may not be blocked. This is because a typical implementation of an MPS is to install it so that it’s not in-line. The MPS receives a copy of the attachment while the original attachment is still delivered to its intended recipient. This is because no conclusion has been made yet about the file. Suppose an MPS does identify the file as malicious. In that case, the MPS might alert the email gateway or another security appliance so that any future download attempts of the same file are blocked.