Network Security Hacks

Get a List of Open Files and Their Owning Processes

Look for suspicious activity by monitoring file accesses.

Suppose you’re looking at the list of processes in the task manager one day after noticing some odd behavior on your workstation, and you notice a process you haven’t seen before. Well, what do you do now? If you were running something other than Windows, you might try to determine what the process is doing by looking at the files it has open. Unfortunately, Windows doesn’t provide a tool to do this.

Sysinternals makes an excellent tool called Handle, which is available for free at http://www.sysinternals.com/ntw2k/freeware/handle.shtml. Handle is a lot like lsof [Hack #8] , but it can list many other types of operating resources, including threads, events, and semaphores. It can also display open registry keys and IOCompletion structures.

Running handle without any command-line arguments will list all open file handles on the system. You can also specify a filename, which will list the processes that are currently accessing it, by typing this:

C:\> handle 
            filename

Or you can list only files that are opened by a particular process—in this case Internet Explorer:

C:\> handle -p iexplore Handle v2.10 Copyright (C) 1997-2003 Mark Russinovich Sysinternals - www.sysinternals.com ---------------------------------------------------------------------------- IEXPLORE.EXE pid: 688 PLUNDER\andrew 98: Section \BaseNamedObjects\MTXCOMM_MEMORY_MAPPED_FILE 9c: Section \BaseNamedObjects\MtxWndList ...