Disclaimer
As usual, this code and tool should not be used for malicious purposes.
Written by Vincent Yiu of MDSec Consulting's ActiveBreach team. Modification of code is allowed with credits to author.
Explorer and SWBemLocator COM Moniker research is by @enigma0x3
morphHTA
Usage:
usage: morph-hta.py [-h] [--in <input_file>] [--out <output_file>]
[--maxstrlen <default: 1000>] [--maxvarlen <default: 40>]
[--maxnumsplit <default: 10>]
optional arguments:
-h, --help show this help message and exit
--in <input_file> File to input Cobalt Strike PowerShell HTA
--out <output_file> File to output the morphed HTA to
--maxstrlen <default: 1000>
Max length of randomly generated strings
--maxvarlen <default: 40>
Max length of randomly generated variable names
--maxnumsplit <default: 10>
Max number of times values should be split in chr
obfuscation
Examples:
/morphHTA# python morph-hta.py
ο»Ώββββ ββββ βββββββ βββββββ βββββββ βββ βββ βββ ββββββββββββ ββββββ
βββββ βββββββββββββββββββββββββββββββββ βββ βββ ββββββββββββββββββββ
ββββββββββββββ βββββββββββββββββββββββββββββββββββββββββ βββ ββββββββ
ββββββββββββββ ββββββββββββββββββ ββββββββββββββββββββββ βββ ββββββββ
βββ βββ βββββββββββββββ ββββββ βββ βββ βββ βββ βββ βββ βββ
βββ βββ βββββββ βββ ββββββ βββ βββ βββ βββ βββ βββ βββ
Morphing Evil.HTA from Cobalt Strike
Author: Vincent Yiu (@vysec, @vysecurity)
[*] morphHTA initiated
[+] Writing payload to morph.hta
[+] Payload written
Max variable name length and randomly generated string length reduced to reduce overall size of HTA output:
/morphHTA# python morph-hta.py --maxstrlen 4 --maxvarlen 4
Max split in chr() obfuscation, this reduces the number of additions we do to reduce length:
/morphHTA# python morph-hta.py --maxnumsplit 4
Change input file and output files:
/morphHTA# python morph-hta.py --in advert.hta --out advert-morph.hta
Video how to
https://www.youtube.com/watch?v=X4S2aQ4o_jA
VirusTotal Example
I suggest not uploading to VT:
Example of Obfuscated HTA content
