YARA · Volexity threat-intel
VOLEXITY_Apt_Webshell_Java_Orangetail
Detection for ORANGETAIL, a custom Java webshell used by UTA0533.
- Author
- threatintel@volexity.com
- Date
- 2026-07-06
- Modified
- 2026-07-14
- Score / Quality
- 75 / 80
What this rule detects
Detection for ORANGETAIL, a custom Java webshell used by UTA0533.
It defines 6 patterns (6 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule VOLEXITY_Apt_Webshell_Java_Orangetail : UTA0533 ORANGETAIL FILE MEMORY
{
meta:
= "Detection for ORANGETAIL, a custom Java webshell used by UTA0533."
= "threatintel@volexity.com"
= "5bbffb5f-0917-57e4-a7d4-f5c770b5d253"
= "2026-07-06"
= "2026-07-14"
= "https://github.com/volexity/threat-intel"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2026/2026-07-17 SonicWall/rules.yar#L26-L53"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
= "ea9154e374e4f77bc2cf54282e23543573980342a85bc888cb23f20b8bbba081"
= "1a495df2bc13b1c2c61315d76d66b150452b923afa5847121429fa8ae9788a7b"
= 75
= 80
= "UTA0533, ORANGETAIL, FILE, MEMORY"
= "all"
= "all"
= "file,memory"
= "critical"
= "TIB-20260714B"
= "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
= 13239
= 5
strings:
$s1 = "agentmain called args="
$s2 = "tryInject="
$s3 = "agentmain ex:"
$s4 = "javassist="
$s5 = "tryInject exception"
$s6 = "found loaded class:"
condition:
4 of ( $s* )
}
Strings (6 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $s1 | text | "agentmain called args=" | |
| $s2 | text | "tryInject=" | |
| $s3 | text | "agentmain ex:" | |
| $s4 | text | "javassist=" | |
| $s5 | text | "tryInject exception" | |
| $s6 | text | "found loaded class:" |
Condition
4 of ( $s* )In plain words (Heuristic)
- At least 4 patterns in ( $s* ) 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).
- ea9154e374e4f77bc2cf54282e23543573980342a85bc888cb23f20b8bbba081
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: 5bbffb5f-0917-57e4-a7d4-f5c770b5d253
Metadata
| os | all |
|---|---|
| os_arch | all |
| scan_context | file,memory |
| severity | critical |
| report1 | TIB-20260714B |
| rule_id | 13239 |
| version | 5 |
Tags:UTA0533ORANGETAILFILEMEMORY
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