YARA · SEKOIA.IO Community
SEKOIA_Apt_Toneshell_Shellcode
Detects first bytes of ToneShell used to call the shellcode or the code to check the MagicNumber (0x17 0x03 0x03)
- Author
- Sekoia.io
- Date
- 2024-10-02
- Modified
- 2024-12-19
- Score / Quality
- 75 / 80
What this rule detects
Detects first bytes of ToneShell used to call the shellcode or the code to check the MagicNumber (0x17 0x03 0x03)
It defines 2 patterns (0 text, 2 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
apt-toneshell-shellcode.yarDetection Rule License 1.1
rule SEKOIA_Apt_Toneshell_Shellcode : FILE
{
meta:
= "Detects first bytes of ToneShell used to call the shellcode or the code to check the MagicNumber (0x17 0x03 0x03)"
= "Sekoia.io"
= "5ac8d2e9-dbeb-42f9-8343-1281510d4411"
= "2024-10-02"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_toneshell_shellcode.yar#L1-L34"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "0e164677681dce2aa75d3621d9f3df1449c3e67a3551817693856d80ccc48eca"
= 75
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$code = {55 8b ec 83 ec 0c e8 85 00 00 00 6a 00 6a 00 6a 02 6a 00 6a 00 68 00 00 00 10}
$MagicNumberParser = {
B8 01 00 00 00
6B C8 00
8B 55 ??
0F BE 04 0A
83 F8 17
75 ??
B9 01 00 00 00
C1 E1 00
8B 55 ??
0F BE 04 0A
83 F8 03
75 ??
B9 01 00 00 00
D1 E1
8B 55 ??
0F BE 04 0A
83 F8 03
}
condition:
any of them and filesize < 1MB
}
Strings (2 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $code | hex | {55 8b ec 83 ec 0c e8 85 00 00 00 6a 00 6a 00 6a 02 6a 00 6a 00 68 00 00 00 10} | |
| $MagicNumberParser | hex | { B8 01 00 00 00 6B C8 00 8B 55 ?? 0F BE 04 0A 83 F8 17 75 ?? B9 01 00 00 00 C1 E1 00 8B … |
Condition
any of them and filesize < 1MBIn plain words (Heuristic)
- The file must be smaller than 1MB (a cheap guard that skips large files).
- At least one pattern in the rule must match.
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References
Licence & attribution
Author: Sekoia.io
Source repository: SEKOIA.IO Community @ a438a5901a
Licence: Detection Rule License 1.1 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 5ac8d2e9-dbeb-42f9-8343-1281510d4411
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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