YARA · Volexity threat-intel
VOLEXITY_Apt_Delivery_Web_Js_Jmask_Str_Array_Variant
Detects the JMASK profiling script in an obfuscated format using a string array and an offset.
- Author
- threatintel@volexity.com
- Date
- 2023-06-27
- Modified
- 2023-09-21
- Score / Quality
- 75 / 80
What this rule detects
Detects the JMASK profiling script in an obfuscated format using a string array and an offset.
It defines 17 patterns (17 text, 0 hex, 0 regex).
YARA-X says: warning[duplicate_pattern_value]: duplicate pattern value
Summary generated from the rule's metadata and condition.
Rule source
rule VOLEXITY_Apt_Delivery_Web_Js_Jmask_Str_Array_Variant : EVILBAMBOO FILE
{
meta:
= "Detects the JMASK profiling script in an obfuscated format using a string array and an offset."
= "threatintel@volexity.com"
= "d5d32c8b-53fb-5103-ac73-05f320e71c97"
= "2023-06-27"
= "2023-09-21"
= "https://github.com/volexity/threat-intel"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2023/2023-09-22 EvilBamboo/indicators/rules.yar#L408-L444"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
= "7995c382263f8dbbfc37a9d62392aef8b4f89357d436b3dd94dea842f9574ecf"
= "0ae7c96e0f866f21d66d7a23bf937d6ce48c9dd1ea19142dbb13487208780146"
= 75
= 80
= "EVILBAMBOO, FILE"
= "file"
= "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
strings:
$array_1 = "http://eular.github.io"
$array_2 = "stun:stun.services.mozilla.com"
$array_3 = "\xE6\x9C\xAA\xE5\xAE\x89\xE8\xA3\x85MetaMask"
$array_4 = "/jquery/jquery.min.js"
$array_5 = "onicecandidate"
$ios_1 = "['a7', '640x1136', [_0x"
$ios_2 = "['a7', _0x"
$ios_3 = "['a8', _0x"
$ios_4 = "['a8', '750x1334', ['iPhone\\x206']]"
$ios_5 = "['a8', '1242x2208', ['iPhone\\x206\\x20Plus']]"
$ios_6 = "['a8', _0x"
$ios_7 = "['a9', _0x"
$ios_8 = "['a9', '750x1334', [_0x"
$ios_9 = "['a9', '1242x2208', ['iPhone\\x206s\\x20Plus']]"
$ios_10 = "['a9x', '2048x2732', ['iPad\\x20Pro\\x20(1st\\x20gen\\x2012.9-inch)']]"
$ios_11 = "['a10x', '1668x2224', [_0x"
$header = "info = {}, finished = 0x0;"
condition:
3 of ( $array_* ) or 5 of ( $ios_* ) or $header
}
Strings (17 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $array_1 | text | "http://eular.github.io" | |
| $array_2 | text | "stun:stun.services.mozilla.com" | |
| $array_3 | text | "\xE6\x9C\xAA\xE5\xAE\x89\xE8\xA3\x85MetaMask" | |
| $array_4 | text | "/jquery/jquery.min.js" | |
| $array_5 | text | "onicecandidate" | |
| $ios_1 | text | "['a7', '640x1136', [_0x" | |
| $ios_2 | text | "['a7', _0x" | |
| $ios_3 | text | "['a8', _0x" | |
| $ios_4 | text | "['a8', '750x1334', ['iPhone\\x206']]" | |
| $ios_5 | text | "['a8', '1242x2208', ['iPhone\\x206\\x20Plus']]" | |
| $ios_6 | text | "['a8', _0x" | |
| $ios_7 | text | "['a9', _0x" | |
| $ios_8 | text | "['a9', '750x1334', [_0x" | |
| $ios_9 | text | "['a9', '1242x2208', ['iPhone\\x206s\\x20Plus']]" | |
| $ios_10 | text | "['a9x', '2048x2732', ['iPad\\x20Pro\\x20(1st\\x20gen\\x2012.9-inch)']]" | |
| $ios_11 | text | "['a10x', '1668x2224', [_0x" | |
| $header | text | "info = {}, finished = 0x0;" |
Condition
3 of ( $array_* ) or 5 of ( $ios_* ) or $headerIn plain words (Heuristic)
- At least 3 patterns in ( $array_* ) must match.
- At least 5 patterns in ( $ios_* ) must match.
- Pattern $header must be present.
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).
- 7995c382263f8dbbfc37a9d62392aef8b4f89357d436b3dd94dea842f9574ecf
Licence & attribution
Author: threatintel@volexity.com
Source repository: Volexity threat-intel @ 3a9d0b5245
Licence: BSD 2-Clause License (stated in the rule's own meta)
“See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt”
Copyright notice: Copyright 2022 by Volexity, Inc.
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: d5d32c8b-53fb-5103-ac73-05f320e71c97
Metadata
| scan_context | file |
|---|
Tags:EVILBAMBOOFILE
Related rules
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-06-15
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-06-01
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-05-25
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2024-07-30
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-07-21
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-08-17
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2023-03-30
- APT / threat actorVolexity threat-intel· threatintel@volexity.com· 2022-11-03