Implementing Linux specific checks
In this section, we will describe how to implement some integrity checks to support the finding signs of system manipulation in Linux and similar (for example, BSD) systems.
These checks include the following:
- Searching for anomalies in the local user management
- Understanding and analyzing file metadata for special permissions and privileges
- Using clustering algorithms on file metadata to get indicators on where to look deeper
Checking the integrity of local user credentials
The information about local users in Linux is mostly stored in two files:
/etc/shadow. The latter is optional and all the information about local users—including the hashed password—was originally stored in
/etc/passwd. Soon, it ...