telfhash 0.9.8

# Trend Micro ELF Hash (telfhash)

telfhash is symbol hash for ELF files, just like imphash is imports hash for PE files.

## Installation

### Requirements

telfhash uses TLSH in generating the hash. TLSH must be installed in your system in order for telfhash to work.

You can install TLSH from here:

• [https://github.com/trendmicro/tlsh/](https://github.com/trendmicro/tlsh/)

The TLSH git repo has detailed instructions on how to compile and install the TLSH binaries and libraries. Don’t forget to also install the TLSH Python library. telfhash uses the TLSH Python library to generate the actual hash.

### Installing

Clone the telfhash repository from here:

• [https://github.com/trendmicro/telfhash](https://github.com/trendmicro/telfhash)

Use the setup.py to install the telfhash library:

python setup.py install

## Usage

If the TLSH Python library is not installed, telfhash will generate an exception error.

### Command line

If telfhash was installed via the python setup.py install command, the telfhash executable will by made available.

$ telfhash -h usage: telfhash.py [-h] [-g] [-t THRESHOLD] [-r] [-d] files [files …]

positional arguments:

files Target ELF file(s). Accepts wildcards

optional arguments:

-h, --help

show this help message and exit

-g, --group

Group the files according to how close their telfhashes are

-t THRESHOLD, --threshold THRESHOLD

Minimum distance betweeen telfhashes to be considered as related. Only works with -g/–group. Defaults to 50

-r, --recursive

Deep dive into all the subfolders. Input should be a folder

-d, --debug

Print debug messages

$ telfhash /bin/trace* /bin/tracepath 09d097025c0b40af18cb0c08ac3f2f5df100d850483bc1404f108809113290a2d6ae4f /bin/traceroute 65e02002d9b9552f56f35e709caf6fa57115f841e83b87148f04b592c023542ed0549f /bin/traceroute6 65e02002d9b9552f56f35e709caf6fa57115f841e83b87148f04b592c023542ed0549f

$ telfhash -g /sbin/ip* /sbin/ip 33c15268ac66484d58be0e68ed2d7e68c25b5b97edf02b10dff4c412d2c3586725f01b /sbin/ip6tables 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ip6tables-legacy 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ip6tables-legacy-restore 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ip6tables-legacy-save 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ip6tables-restore 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ip6tables-save 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/ipmaddr 7dc08c0a6622ad4b2af66e781c3322864248e073b06ccb56aaaf854088062091c6011c /sbin/ipset e4a0029085e66bce4ed2146959136540409454e38028d780613002a6d70154d5023d6a /sbin/iptables 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptables-apply - /sbin/iptables-legacy 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptables-legacy-restore 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptables-legacy-save 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptables-restore 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptables-save 083169fc5722ee8734bfb9357cf23b41a5092db0b9a8d0a95d08d743464636ca143c66 /sbin/iptstate 1ef02223f4318ca385920c9910f975a131268721a1dbb80dff038e758bad21e65718cf /sbin/iptunnel d5c08c4aa612ad5b3ae72e781c3330868248e0b2b05c8b52aa2a854089062090c60518

Group 1:

/sbin/ipmaddr /sbin/iptunnel

Group 2:

/sbin/ip6tables /sbin/ip6tables-legacy /sbin/ip6tables-legacy-restore /sbin/ip6tables-legacy-save /sbin/ip6tables-restore /sbin/ip6tables-save /sbin/iptables /sbin/iptables-legacy /sbin/iptables-legacy-restore /sbin/iptables-legacy-save /sbin/iptables-restore /sbin/iptables-save

Cannot be grouped:

/sbin/iptstate /sbin/ipset /sbin/ip

### Python module

>>> import telfhash
>>> import pprint
>>> telfhash.telfhash("/bin/ping")
{'file': '/bin/ping', 'telfhash': '6901d303587a847f9aa30ce44c3f3f5c6101e9525eb2d354cf1297948022b40aa4a99f', 'msg': ''}
>>>
>>> results = telfhash.telfhash("telfhash/tests/samples/hdumps/*")
>>> groups = telfhash.group(results)
>>> pprint.pprint(groups)
{'grouped': (('telfhash/tests/samples/hdumps/hdump_32_so_stat_stripped',
              'telfhash/tests/samples/hdumps/hdump_32_stat_stripped'),
             ('telfhash/tests/samples/hdumps/hdump_64_so_stat_stripped',
              'telfhash/tests/samples/hdumps/hdump_64_stat_stripped'),
             ('telfhash/tests/samples/hdumps/hdump_32_so_stat',
              'telfhash/tests/samples/hdumps/hdump_32_stat',
              'telfhash/tests/samples/hdumps/hdump_64_so_stat',
              'telfhash/tests/samples/hdumps/hdump_64_stat',
              'telfhash/tests/samples/hdumps/hdump_static'),
             ('telfhash/tests/samples/hdumps/hdump',
              'telfhash/tests/samples/hdumps/hdump32',
              'telfhash/tests/samples/hdumps/hdump_32_dyn',
              'telfhash/tests/samples/hdumps/hdump_32_dyn_stripped',
              'telfhash/tests/samples/hdumps/hdump_32_so_dyn',
              'telfhash/tests/samples/hdumps/hdump_32_so_dyn_stripped',
              'telfhash/tests/samples/hdumps/hdump_64_dyn',
              'telfhash/tests/samples/hdumps/hdump_64_dyn_stripped',
              'telfhash/tests/samples/hdumps/hdump_64_so_dyn',
              'telfhash/tests/samples/hdumps/hdump_64_so_dyn_stripped',
              'telfhash/tests/samples/hdumps/hdump_dynamic',
              'telfhash/tests/samples/hdumps/hdump_stripped')),
 'nogroup': []}
>>>
>>> telfhash.telfhash("samples/LinuxMoose/LinuxMoose.arm7.2015.0.bin")
{'file': 'samples/LinuxMoose/LinuxMoose.arm7.2015.0.bin', 'telfhash': None, 'msg': 'No symbols found'}
>>> telfhash.telfhash("/bin/ls", "/bin/lsattr")
[{'file': '/bin/ls', 'telfhash': '1ff0994248230af71762c8b15c0533da9a208b2656e5bf302f1985d04e2a5be779284f', 'msg': ''}, {'file': '/bin/lsattr', 'telfhash': '69c08017dd0fe4f35dd90d589c07380ae7dee06057b9d7400d3c46c1755058c5d5555d', 'msg': ''}]

## Publications / Resources

• [Similarity brings your threat hunting to the next level](https://www.brighttalk.com/webcast/18282/452440) - VirusTotal / Trend Micro / Trinity Cyber - November 25, 2020

• [VirusTotal Now Supports Trend Micro ELF Hash](https://www.trendmicro.com/en_us/research/20/j/virustotal-now-supports-trend-micro-elf-hash.html) - Trend Micro Research - October 13, 2020

• [Grouping Linux IoT Malware Samples With Trend Micro ELF Hash aka telfash](https://blog.trendmicro.com/trendlabs-security-intelligence/) - Trend Micro Blog - April 20, 2020.