Linux Security

Detecting and Investigating OpenSSL Backdoors on Linux

April 18, 2021

A nightmare for security personnel on Linux is to find a backdoor operating. This means an attacker is interacting with the host in real-time to further their intrusion. Of various backdoors that can…

Linux Malware Investigation Myth: You Don’t Need a Debugger

January 18, 2021

A big myth around investigating Linux ransomware and malware is that the first tool you need is a debugger and deep knowledge of assembly to understand what it does. It’s easy for admins and security…

Investigating Linux Process File Descriptors for Incident Response and Forensics

January 06, 2021

Let’s talk about Linux file descriptors and how to investigate a malicious process using them. What Is a File Descriptor? Since the inception of Unix (on which Linux is based), everything is a file.…

Getting In The Fight

September 03, 2020

Let’s talk about how to be effective detecting intruders. Or what we at Sandfly Security simply call: Getting in the fight . First to lay some groundwork, the policy of Sandfly Security is that we…

Linux Stealth Rootkit Process Decloaking Tool – sandfly-processdecloak

August 16, 2020

We have released a new tool called sandfly-processdecloak to help find and decloak Linux stealth rootkits automatically. This tool was released as a response to the disclosure by the FBI and NSA of a…

Detecting Linux memfd_create() Fileless Malware with Command Line Forensics

July 08, 2020

A developing threat to Linux over the last several years has been the idea of fileless malware. Fileless Linux malware is difficult to detect. It's designed to inject itself into a running Linux…