YARA · Signature Base (Florian Roth / Nextron)
SIGNATURE_BASE_APT_UNC4841_ESG_Barracuda_CVE_2023_2868_Forensic_Artifacts_Jun23_1
Detects forensic artifacts found in the exploitation of CVE-2023-2868 in Barracuda ESG devices by UNC4841
- Author
- Florian Roth
- Date
- 2023-06-15
- Modified
- 2023-06-16
- Score / Quality
- 75 / 85
What this rule detects
Detects forensic artifacts found in the exploitation of CVE-2023-2868 in Barracuda ESG devices by UNC4841
It defines 12 patterns (12 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule SIGNATURE_BASE_APT_UNC4841_ESG_Barracuda_CVE_2023_2868_Forensic_Artifacts_Jun23_1 : SCRIPT CVE_2023_2868
{
meta:
= "Detects forensic artifacts found in the exploitation of CVE-2023-2868 in Barracuda ESG devices by UNC4841"
= "Florian Roth"
= "50518fa1-33de-5fe5-b957-904d976fb29a"
= "2023-06-15"
= "2023-06-16"
= "https://www.mandiant.com/resources/blog/barracuda-esg-exploited-globally"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_barracuda_esg_unc4841_jun23.yar#L2-L28"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
= "fa7cac1e0f6cb6fa3ac271c1fff0039ff182b6859920b4eca25541457654acde"
= 75
= 85
= "SCRIPT, CVE-2023-2868"
strings:
$x01 = "=;ee=ba;G=s;_ech_o $abcdefg_${ee}se64" ascii
$x02 = ";echo $abcdefg | base64 -d | sh" ascii
$x03 = "setsid sh -c \"mkfifo /tmp/p" ascii
$x04 = "sh -i </tmp/p 2>&1" ascii
$x05 = "if string.match(hdr:body(), \"^[%w%+/=" ascii
$x06 = "setsid sh -c \"/sbin/BarracudaMailService eth0\""
$x07 = "echo \"set the bvp ok\""
$x08 = "find ${path} -type f ! -name $excludeFileNameKeyword | while read line ;"
$x09 = " /mail/mstore | xargs -i cp {} /usr/share/.uc/"
$x10 = "tar -T /mail/mstore/tmplist -czvf "
$sa1 = "sh -c wget --no-check-certificate http"
$sa2 = ".tar;chmod +x "
condition:
1 of ( $x* ) or all of ( $sa* )
}
Strings (12 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $x01 | text | "=;ee=ba;G=s;_ech_o $abcdefg_${ee}se64" | ascii |
| $x02 | text | ";echo $abcdefg | base64 -d | sh" | ascii |
| $x03 | text | "setsid sh -c \"mkfifo /tmp/p" | ascii |
| $x04 | text | "sh -i </tmp/p 2>&1" | ascii |
| $x05 | text | "if string.match(hdr:body(), \"^[%w%+/=" | ascii |
| $x06 | text | "setsid sh -c \"/sbin/BarracudaMailService eth0\"" | |
| $x07 | text | "echo \"set the bvp ok\"" | |
| $x08 | text | "find ${path} -type f ! -name $excludeFileNameKeyword | while read line ;" | |
| $x09 | text | " /mail/mstore | xargs -i cp {} /usr/share/.uc/" | |
| $x10 | text | "tar -T /mail/mstore/tmplist -czvf " | |
| $sa1 | text | "sh -c wget --no-check-certificate http" | |
| $sa2 | text | ".tar;chmod +x " |
Condition
1 of ( $x* ) or all of ( $sa* )In plain words (Heuristic)
- All patterns in ( $sa* ) must match.
- At least 1 patterns in ( $x* ) must match.
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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: 50518fa1-33de-5fe5-b957-904d976fb29a
Tags:SCRIPTCVE_2023_2868
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