YARA · CAPE Sandbox (CAPEv2)
CAPE_Nitrobunnydownloader
NitroBunnyDownloader
- Author
- enzok
- Date
- 2025-10-28
- Modified
- 2025-11-05
- Score / Quality
- 75 / 70
What this rule detects
NitroBunnyDownloader
Targets: Windows PE.
It defines 7 patterns (5 text, 2 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule CAPE_Nitrobunnydownloader : FILE
{
meta:
= "NitroBunnyDownloader"
= "enzok"
= "64faa91a-4847-57bd-ab71-27029f6074ac"
= "2025-10-28"
= "2025-11-05"
= "https://github.com/kevoreilly/CAPEv2"
= "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/data/yara/CAPE/NitroBunnyDownloader.yar#L1-L18"
= "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
= "960e59200ec0a4b5fb3b44e6da763f5fec4092997975140797d4eec491de411b"
= "dcc1348c1d1af0c854376cf6331538951362b43d8d76c0ad73bbbdeb1ab4c135"
= 75
= 70
= "FILE"
= "NitroBunnyDownloader Payload"
strings:
$config1 = {E8 [3] 00 41 B8 ?? ?? 00 00 48 8D 15 [3] 00 48 89 C1 48 89 ?? E8 [3] 00}
$config2 = {E8 [3] 00 48 8D 15 [3] 00 41 B8 ?? ?? 00 00 48 89 C1 48 89 ?? E8 [3] 00}
$string1 = "X-Amz-User-Agent:" wide
$string2 = "Amz-Security-Flag:" wide
$string3 = "/cart" wide
$string4 = "Cookie: " wide
$string5 = "wishlist" wide
condition:
uint16( 0 ) == 0x5A4D and 1 of ( $config* ) and 2 of ( $string* )
}
Strings (7 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $config1 | hex | {E8 [3] 00 41 B8 ?? ?? 00 00 48 8D 15 [3] 00 48 89 C1 48 89 ?? E8 [3] 00} | |
| $config2 | hex | {E8 [3] 00 48 8D 15 [3] 00 41 B8 ?? ?? 00 00 48 89 C1 48 89 ?? E8 [3] 00} | |
| $string1 | text | "X-Amz-User-Agent:" | wide |
| $string2 | text | "Amz-Security-Flag:" | wide |
| $string3 | text | "/cart" | wide |
| $string4 | text | "Cookie: " | wide |
| $string5 | text | "wishlist" | wide |
Condition
uint16( 0 ) == 0x5A4D and 1 of ( $config* ) and 2 of ( $string* )In plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- At least 1 patterns in ( $config* ) must match.
- At least 2 patterns in ( $string* ) must match.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
References
Sample hashes
Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).
- 960e59200ec0a4b5fb3b44e6da763f5fec4092997975140797d4eec491de411b
Licence & attribution
Author: enzok
Source repository: CAPE Sandbox (CAPEv2) @ 6b15e76f28
Licence: GNU General Public License v3.0 (repository licence)
Copyright notice: Cuckoo Sandbox is copyrighted by the Cuckoo Foundation.
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 64faa91a-4847-57bd-ab71-27029f6074ac
Metadata
| cape_type | NitroBunnyDownloader Payload |
|---|
Tags:FILE
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