Ossec might be a bit more popular than Chkrootkit. We know about 1 link to it since March 2021 and only 1 link to Chkrootkit. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
If you are extremely worried about root kits you would need to start with a clean system and then whitelist any "positives". If your concerned you would have to use the tedious method of using dpkg to determine what package a file belongs to, one at a time, and then compare it's checksum to the back installed... I would also recommend using only the latest version from the website directly http://chkrootkit.org/... Source: almost 3 years ago
I'd take it one step further and install OSSEC as well. It can be configured to run as a local daemon and report suspicious activity, and also intervene. So if somebody is brute-forcing the login on your web page, it'll create a burst of 401s which OSSEC will detect in the logs and block the offender for X minutes/hours. Source: over 2 years ago
GMER - GMER is an application that detects and removes rootkits .
snort - Snort is a free and open source network intrusion prevention system.
TDSSKiller - Kaspersky Lab has developed the TDSSKiller utility that allows removing rootkits.
McAfee Network Security Platform - McAfee Network Security Platform guards all your network-connected devices from zero-day and other attacks, with a cost-effective network intrusion prevention system.
Malwarebytes Anti-Rootkit - Malwarebytes Anti-Rootkit is a rootkit removal program by the Malwarebytes best known for providing the antimalware program.
AIDE - AIDE (Advanced Intrusion Detection Environment) is a file and directory integrity checker.