Preventing File-Based Malware And Botnets

In the current cybersecurity threat landscape, most botnets propagate via exploits and file-based malware. Anything that touches the disk has the ability to be blocked via access controls on the host. However, new malware techniques utilize more than just binaries to execute malicious code, demanding the need for execution control. Kurstis Armour, an Information Security Consultant at cyber security company eSentire commented below.

Kurtis Armour, Information Security Consultant at eSentire:

“The main techniques we see botnets attempting to grow is through malware utilizing JavaScript payloads, standard binaries, macros and PowerShell payloads, with notable delivery techniques through exploitation (exploit kits and malvertising) and social engineering (tricking users into opening bad software). Defense in depth strategies generally focus on preventing the exploit/malware from landing via network access controls. If a threat actor is able to get initial code execution on a machine, it’s up to the access controls on the host system to prevent successful compromise.

One of the most effective ways to protect against compromise is by limiting what someone has the ability to do when they get onto a machine. Consider enforcing these practices within your organization:

• Don’t allow general users to connect to the local administrator account.
• Limit what software can be allowed on the system.
• Disallow the auto-execution of scripts to limit the potential attack surface.
• Change the default execution of specific applications to stop malicious files from being executed when a user double clicks on them.
• Reduce the risk that comes with embedded VBA macros within Microsoft Office documents.
• Enforce application whitelisting rules to ensure only approved applications are executed.”