Sometimes it may start with a simple nagios alarm notification about an unusual high database server CPU load. Since something else was suspicious, the customer called us asking to help him out. We investigated it and detected a possible extraction of sensitive data.
We analysed log information, compared timestamps and checked the corresponding source code of the application itself. We were able to draft up a timetable when the initial hack happened to alter the source code. The attacker modified the source code located directly on the web server to alter some part of the data encryption. In the end, the alarm of the high database server CPU load was the attackers "select * from..." to get all the unencrypted data.
Forensic investigations like this require a very good technical understand of file systems and networks. In addition, a deeper understanding of an attackers mind set and the art of hacking itself helps to develop a hunch where to look.back to projects