YARA · Volexity threat-intel
VOLEXITY_Apt_Delivery_Web_Js_Jmask
Detects the JMASK profiling script in its minified // obfuscated format.
- Author
- threatintel@volexity.com
- Date
- 2023-06-15
- Modified
- 2023-09-21
- Score / Quality
- 75 / 80
What this rule detects
Detects the JMASK profiling script in its minified // obfuscated format.
It defines 8 patterns (8 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule VOLEXITY_Apt_Delivery_Web_Js_Jmask : EVILBAMBOO FILE
{
meta:
= "Detects the JMASK profiling script in its minified // obfuscated format."
= "threatintel@volexity.com"
= "a7b653e1-f7c6-56cc-ab99-3de91d29ef3b"
= "2023-06-15"
= "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#L446-L472"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
= "efea95720853e0cd2d9d4e93a64a726cfe17efea7b17af7c4ae6d3a6acae5b30"
= "64315ac05049954d36297a616a25ffdd7ce81c6313c0878d5ba4082da24c21bb"
= 75
= 80
= "EVILBAMBOO, FILE"
= "file"
= "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
strings:
$rev0 = "oi.buhtig.ralue//:ptth" ascii
$rev1 = "lairA' xp41" ascii
$rev2 = "dnuof ton ksaMateM" ascii
$unicode1 = "document[\"\\u0063\\u0075\\u0072\\u0072\\u0065\\u006e\\u0074\\u0053\\u0063\\u0072\\u0069\\u0070\\u0074\"]" ascii
$unicode2 = "\\u0061\\u0070\\u0070\\u006c\\u0069\\u0063\\u0061\\u0074\\u0069\\u006f\\u006e\\u002f\\u006a\\u0073\\u006f\\u006e" ascii
$unicode3 = "\\u0063\\u006c\\u0069\\u0065\\u006e\\u0074\\u0057\\u0069\\u0064\\u0074\\u0068" ascii
$unicode4 = "=window[\"\\u0073\\u0063\\u0072\\u0065\\u0065\\u006e\"]" ascii
$header = "(function(){info={};finished=" ascii
condition:
all of ( $rev* ) or all of ( $unicode* ) or $header
}
Strings (8 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $rev0 | text | "oi.buhtig.ralue//:ptth" | ascii |
| $rev1 | text | "lairA' xp41" | ascii |
| $rev2 | text | "dnuof ton ksaMateM" | ascii |
| $unicode1 | text | "document[\"\\u0063\\u0075\\u0072\\u0072\\u0065\\u006e\\u0074\\u0053\\u0063\\u0072\\u0069\\u0070\\u0074\"]" | ascii |
| $unicode2 | text | "\\u0061\\u0070\\u0070\\u006c\\u0069\\u0063\\u0061\\u0074\\u0069\\u006f\\u006e\\u002f\\u006a\\u0073\\u006f\\u006e" | ascii |
| $unicode3 | text | "\\u0063\\u006c\\u0069\\u0065\\u006e\\u0074\\u0057\\u0069\\u0064\\u0074\\u0068" | ascii |
| $unicode4 | text | "=window[\"\\u0073\\u0063\\u0072\\u0065\\u0065\\u006e\"]" | ascii |
| $header | text | "(function(){info={};finished=" | ascii |
Condition
all of ( $rev* ) or all of ( $unicode* ) or $headerIn plain words (Heuristic)
- All patterns in ( $rev* ) must match.
- All patterns in ( $unicode* ) 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).
- efea95720853e0cd2d9d4e93a64a726cfe17efea7b17af7c4ae6d3a6acae5b30
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: a7b653e1-f7c6-56cc-ab99-3de91d29ef3b
Metadata
| scan_context | file |
|---|
Tags:EVILBAMBOOFILE
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