rkhunter: add page (#8047)

pages/linux/rkhunter.md

@@ -0,0 +1,24 @@
+# rkhunter
+
+> Searches for rootkits and malware.
+> More information: <https://wiki.archlinux.org/title/Rkhunter>.
+
+- Check a system for rootkits and malware:
+
+`sudo rkhunter --check`
+
+- Update rkhunter:
+
+`sudo rkhunter --update`
+
+- Print all available tests:
+
+`sudo rkhunter --list`
+
+- Display version:
+
+`sudo rkhunter --versioncheck`
+
+- Display help:
+
+`sudo rkhunter --help`