Manpages

NAME

foremost − Recover files using their headers and footers

SYNOPSIS

foremost [-h] [-V] [-vq] [-i <file>] [-o <dir>] [-c <file>] [-s <num>] [FILES]...

DESCRIPTION

Recover files from a disk image based on headers and footers specified by the user.

−h

Show a help screen and exit.

−V

Show copyright information and exit.

−v

Enables verbose mode. This causes more information regarding the current state of the program to be displayed on the screen, and is highly recommended.

−q

Enables quick mode. In quick mode, only the start of each sector is searched for matching headers. That is, the header is searched only up to the length of the longest header. The rest of the sector, usually about 500 bytes, is ignored. This mode makes foremost run considerably faster, but it may cause you to miss files that are embedded in other files. For example, using quick mode you will not be able to find JPEG images embedded in Microsoft Word documents.

Quick mode should not be used when examining NTFS file systems. Because NTFS will store small files inside the Master File Table, these files will be missed during quick mode.

Some users have found that certain headers, such as those for MPEG and Quicktime movies, can be found many times inside MPEG and MOV files. The result can be several dozen incomplete files recovered from a single MPEG file. Using quick mode can help avoid this problem.

−i file

The file file is used as a list of input files to examine. Each line is assumed to consist of a single filename.

-o directory

Recovered files are written to the directory directory. As of version 0.64, foremost requires that this directory is either empty or does not exist. Foremost will create the directory if necessary.

-c file

Sets the configuration file to use. If none is specified, the file "/etc/foremost.conf" is used. The format for the configuration file is described in the default configuration file included with this program. See the CONFIGURATION FILE section below for more information.

-s number

Skips number bytes in each input file before beginning the search for headers.

CONFIGURATION FILE

The configuration file is used to control what types of files foremost searches for. A sample configuration file, foremost.conf, is included with this distribution. For each file type, the configuration file describes the file’s extension, whether the header and footer are case sensitive, the maximum file size, and the header and footer for the file. The footer field is optional, but header, size, case sensitivity, and extension are not!

Any line that begins with a pound sign is considered a comment and ignored. Thus, to skip a file type just put a pound sign at the beginning of that line

Headers and footers are decoded before use. To specify a value in hexadecimal use \x[0-f][0-f], and for octal use \[1-9][1-9][1-9]. Spaces can be represented by \s. Example: "\x4F\123\I\sCCI" decodes to "OSI CCI".

To match any single character (aka a wildcard) use a ’?’. If you need to search for the ’?’ character, you will need to change the ’wildcard’ line *and* every occurrence of the old wildcard character in the configuration file. Don’t forget those hex and octal values! ’?’ is equal to \x3f and \063.

There is a sample set of headers in the README file.

AUTHORS

Written by Special Agent Kris Kendall and Special Agent Jesse Kornblum of the United States Air Force Office of Special Investigations.

BUGS

When compiling foremost on systems with versions of glibc 2.1.x or older, you will get some (harmless) compiler warnings regarding the implicit declaration of fseeko and ftello. You can safely ignore these warnings.

REPORTING BUGS

Because Foremost could be used to obtain evidence for criminal prosecutions, we take all bug reports very seriously. Any bug that jeopardizes the forensic integrity of this program could have serious consequenses on people’s lives. When submitting a bug report, please include a description of the problem, how you found it, and your contact information.

Send bug reports to:
jesse.kornblum [AT] ogn.mil

COPYRIGHT

This program is a work of the US Government. In accordance with 17 USC 105, copyright protection is not available for any work of the US Government.

This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

There is more information in the README file.

Foremost was originally designed to imitate the functionality of CarvThis, a DOS program written by the Defense Computer Forensics Lab in in 1999.