data-manipulation/encryption/rc4
rule:
meta:
name: encrypt data using RC4 via SystemFunction032
namespace: data-manipulation/encryption/rc4
authors:
- richard.weiss@mandiant.com
scopes:
static: function
dynamic: thread
att&ck:
- Defense Evasion::Obfuscated Files or Information [T1027]
mbc:
- Defense Evasion::Obfuscated Files or Information::Encryption-Standard Algorithm [E1027.m05]
- Cryptography::Encrypt Data::RC4 [C0027.009]
references:
- https://doxygen.reactos.org/df/d13/sysfunc_8c_source.html
- https://blog.gentilkiwi.com/tag/systemfunction032
examples:
- 3BBDF04C25FCD9876733EAA9163B3ED64D81396E7414619758D9376EDF4C103E:0x1000976C # api match
features:
- or:
- api: SystemFunction032
- and:
- match: link function at runtime on Windows
- string: "SystemFunction032"
- optional:
- string: /advapi32/i
- string: /cryptsp/i
last edited: 2023-11-24 10:53:19