Looking for intruders with lsof
QUICK CHECK
Track down and expose intruders with the versatile admin tool lsof.
Has your server been cracked? Are your processes running wild? If you suspect an intrusion, you’ll need accurate information on what’s happening with the system. Open file handles are a useful source for this information. lsof scans the depths of the filesystem for these files and then returns comprehensive and detailed output.
To be fully prepared for an attack, you’ll need an Intrusion Detection System (IDS) like Snort, Tripwire or Aide to check the filesystem and data streams for suspicious patterns. However, if you don’t have the time or resources for a full-blown intrusion response, Linux has a number of standard command line programs capable of discovering tell-tale traces on a system. The usual suspects for server diagnosis are ps, netstat, top, fuser, and other friendly helpers.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.
News
-
Arch Linux 2023.12.01 Released with a Much-Improved Installer
If you've ever wanted to install Arch Linux, now is your time. With the latest release, the archinstall script vastly simplifies the process.
-
Zorin OS 17 Beta Available for Testing
The upcoming version of Zorin OS includes plenty of improvements to take your PC to a whole new level of user-friendliness.
-
Red Hat Migrates RHEL from Xorg to Wayland
If you've been wondering when Xorg will finally be a thing of the past, wonder no more, as Red Hat has made it clear.
-
PipeWire 1.0 Officially Released
PipeWire was created to take the place of the oft-troubled PulseAudio and has finally reached the 1.0 status as a major update with plenty of improvements and the usual bug fixes.
-
Rocky Linux 9.3 Available for Download
The latest version of the RHEL alternative is now available and brings back cloud and container images for ppc64le along with plenty of new features and fixes.
-
Ubuntu Budgie Shifts How to Tackle Wayland
Ubuntu Budgie has yet to make the switch to Wayland but with a change in approaches, they're finally on track to making it happen.
-
TUXEDO's New Ultraportable Linux Workstation Released
The TUXEDO Pulse 14 blends portability with power, thanks to the AMD Ryzen 7 7840HS CPU.
-
AlmaLinux Will No Longer Be "Just Another RHEL Clone"
With the release of AlmaLinux 9.3, the distribution will be built entirely from upstream sources.
-
elementary OS 8 Has a Big Surprise in Store
When elementary OS 8 finally arrives, it will not only be based on Ubuntu 24.04 but it will also default to Wayland for better performance and security.
-
OpenELA Releases Enterprise Linux Source Code
With Red Hat restricting the source for RHEL, it was only a matter of time before those who depended on that source struck out on their own.