yara - Man Page

find files matching patterns and rules written in a special-purpose language.

Synopsis

yara [OPTION]... [NAMESPACE:]RULES_FILE... FILE | DIR | PID

Description

yara scans the given FILE, all files contained in directory DIR, or the process identified by PID looking for matches of patterns and rules provided in a special purpose-language. The rules are read from one or more RULES_FILE.

The options to yara(1) are:

   --atom-quality-table

Path to a file with the atom quality table.

-C  --compiled-rules

RULES_FILE contains rules already compiled with yarac.

-c  --count

Print number of matches only.

-d  --define=identifier=value

Define an external variable. This option can be used multiple times.

   --fail-on-warnings

Treat warnings as errors. Has no effect if used with --no-warnings.

-f  --fast-scan

Speeds up scanning by searching only for the first occurrence of each pattern.

-i identifier --identifier=identifier

Print rules named identifier and ignore the rest. This option can be used multiple times.

   --max-process-memory-chunk=size

While scanning process memory read data in chunks of the given size in bytes.

-l number --max-rules=number

Abort scanning after a number of rules matched.

   --max-strings-per-rule=number

Set maximum number of strings per rule (default=10000)

-x  --module-data=module=file

Pass file's content as extra data to module. This option can be used multiple times.

-n  --negate

Print rules that doesn't apply (negate).

-w  --no-warnings

Disable warnings.

-m  --print-meta

Print metadata associated to the rule.

-D  --print-module-data

Print module data.

-M  --module-names

show module names

-e  --print-namespace

Print namespace associated to the rule.

-S  --print-stats

Print rules' statistics.

-s  --print-strings

Print strings found in the file.

-L  --print-string-length

Print length of strings found in the file.

-X  --print-xor-key

Print xor key of matched strings.

-g  --print-tags

Print the tags associated to the rule.

-r  --recursive

Scan files in directories recursively. It follows symlinks.

   --scan-list

Scan files listed in FILE, one per line.

-z size --skip-larger=size

Skip files larger than the given size in bytes when scanning a directory.

-k slots --stack-size=slots

Set maximum stack size to the specified number of slots.

   --strict-escape

Print warnings if rules contain ambiguous escape statements.

-t tag --tag=tag

Print rules tagged as tag and ignore the rest. This option can be used multiple times.

-p number --threads=number

Use the specified number of threads to scan a directory.

-a seconds --timeout=seconds

Abort scanning after a number of seconds has elapsed.

-v  --version

Show version information.

Examples

$ yara /foo/bar/rules .

Apply rules on /foo/bar/rules to all files on current directory. Subdirectories are not scanned.

$ yara -t Packer -t Compiler /foo/bar/rules bazfile

Apply rules on /foo/bar/rules to bazfile. Only reports rules tagged as Packer or Compiler.

$ cat /foo/bar/rules | yara -r /foo

Scan all files in the /foo directory and its subdirectories. Rules are read from standard input.

$ yara -d mybool=true -d myint=5 -d mystring="my string" /foo/bar/rules bazfile

Defines three external variables mybool myint and mystring.

$ yara -x cuckoo=cuckoo_json_report /foo/bar/rules bazfile

Apply rules on /foo/bar/rules to bazfile while passing the content of cuckoo_json_report to the cuckoo module.

Author

Victor M. Alvarez <plusvic@gmail.com>;<vmalvarez@virustotal.com>

Referenced By

yarac(1).

September 22, 2008 Victor M. Alvarez