OPERATING SYSTEM (OS) DETECTION

Operating System detection is a technique to determine the Operating System running on the target PC, then exploit vulnerabilities associated with that Operating System.

• Each company has its own way of implementing the TCP/IP stack, so it responds to certain scans in its unique way, which determines the OS.
• An exact query sent to one OS will respond differently from the exact same query sent to different OS, usually allows us to enumerate information about the Operating System.
• Some OSes run particular services on certain ports, so OS can be determined if these ports are open. Example : If ports 137, 138, 139, 445 are open on a system, it is Windows 2000

You have an idea how OS Detection works. Lets study OS DETECTION STRATEGIES in detail.

TOOLS : NMap, CHECKOS