YARA · Signature Base (Florian Roth / Nextron)
SIGNATURE_BASE_MAL_MSI_Mpyutils_Feb24_1
Detects malicious MSI package mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709
- Author
- Florian Roth
- Date
- 2024-02-23
- Modified
- 2024-04-24
- Score / Quality
- 70 / 85
What this rule detects
Detects malicious MSI package mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709
It defines 3 patterns (3 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule SIGNATURE_BASE_MAL_MSI_Mpyutils_Feb24_1 : CVE_2024_1708 CVE_2024_1709 FILE
{
meta:
= "Detects malicious MSI package mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709"
= "Florian Roth"
= "e7794336-a325-5b92-8c25-81ed9cb28044"
= "2024-02-23"
= "2024-04-24"
= "https://www.huntress.com/blog/slashandgrab-screen-connect-post-exploitation-in-the-wild-cve-2024-1709-cve-2024-1708"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_connectwise_screenconnect_vuln_feb24.yar#L230-L247"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
= "8e51de4774d27ad31a83d5df060ba008148665ab9caf6bc889a5e3fba4d7e600"
= "ba20db486e5d3c29c9702e10628fb3c0e55e52bbec74e3a86ed6511a6475b82f"
= 70
= 85
= "CVE-2024-1708, CVE-2024-1709, FILE"
strings:
$s1 = "crypt64ult.exe" ascii fullword
$s2 = "EXPAND.EXE" wide fullword
$s6 = "ICACLS.EXE" wide fullword
condition:
uint16( 0 ) == 0xcfd0 and filesize < 20000KB and all of them
}
Strings (3 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $s1 | text | "crypt64ult.exe" | ascii fullword |
| $s2 | text | "EXPAND.EXE" | wide fullword |
| $s6 | text | "ICACLS.EXE" | wide fullword |
Condition
uint16( 0 ) == 0xcfd0 and filesize < 20000KB and all of themIn plain words (Heuristic)
- The file must be smaller than 20000KB (a cheap guard that skips large files).
- 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.
Sample hashes
Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).
- 8e51de4774d27ad31a83d5df060ba008148665ab9caf6bc889a5e3fba4d7e600
Licence & attribution
Author: Florian Roth
Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a
Licence: Detection Rule License 1.1 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: e7794336-a325-5b92-8c25-81ed9cb28044
Tags:CVE_2024_1708CVE_2024_1709FILE
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