YARA · Volexity threat-intel
VOLEXITY_Malware_Win_Iis_Shellsave
Detects an AutoIT backdoor designed to run on IIS servers and to install a webshell.
- Author
- threatintel@volexity.com
- Date
- 2021-11-17
- Modified
- 2023-08-17
- Score / Quality
- 75 / 80
What this rule detects
Detects an AutoIT backdoor designed to run on IIS servers and to install a webshell.
It defines 4 patterns (4 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule VOLEXITY_Malware_Win_Iis_Shellsave : WHEELEDASH FILE MEMORY
{
meta:
= "Detects an AutoIT backdoor designed to run on IIS servers and to install a webshell."
= "threatintel@volexity.com"
= "a89defa5-4b22-5650-a0c0-f4b3cf3377a7"
= "2021-11-17"
= "2023-08-17"
= "https://github.com/volexity/threat-intel"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2021/2021-12-06 - XEGroup/indicators/yara.yar#L27-L49"
= "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
= "21683e02e11c166d0cf616ff9a1a4405598db7f4adfc87b205082ae94f83c742"
= "f34d6f4ecaa4cde5965f6b0deac55c7133a2be96f5c466f34775be6e7f730493"
= 75
= 80
= "WHEELEDASH, FILE, MEMORY"
= "file,memory"
= "high"
= "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
= 6146
= 4
strings:
$s1 = "getdownloadshell" ascii
$s2 = "deleteisme" ascii
$s3 = "sitepapplication" ascii
$s4 = "getapplicationpool" ascii
condition:
all of them
}
Strings (4 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $s1 | text | "getdownloadshell" | ascii |
| $s2 | text | "deleteisme" | ascii |
| $s3 | text | "sitepapplication" | ascii |
| $s4 | text | "getapplicationpool" | ascii |
Condition
all of themIn plain words (Heuristic)
- All patterns in the rule 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).
- 21683e02e11c166d0cf616ff9a1a4405598db7f4adfc87b205082ae94f83c742
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: a89defa5-4b22-5650-a0c0-f4b3cf3377a7
Metadata
| scan_context | file,memory |
|---|---|
| severity | high |
| rule_id | 6146 |
| version | 4 |
Tags:WHEELEDASHFILEMEMORY
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