The detection identifies potential exploitation of the Equation Group hack tool, ebbshave.v5, which may indicate unauthorized access or data exfiltration by advanced adversaries. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate potential breaches from known sophisticated threat actors.
YARA Rule
rule EquationGroup_ebbshave {
meta:
description = "Equation Group hack tool leaked by ShadowBrokers- file ebbshave.v5"
author = "Florian Roth"
reference = "https://medium.com/@shadowbrokerss/dont-forget-your-base-867d304a94b1"
date = "2017-04-08"
hash1 = "eb5e0053299e087c87c2d5c6f90531cc1946019c85a43a2998c7b66a6f19ca4b"
strings:
$s1 = "executing ./ebbnew_linux -r %s -v %s -A %s %s -t %s -p %s" fullword ascii
$s2 = "./ebbnew_linux.wrapper -o 2 -v 2 -t 192.168.10.4 -p 32772" fullword ascii
$s3 = "version 1 - Start with option #18 first, if it fails then try this option" fullword ascii
$s4 = "%s is a wrapper program for ebbnew_linux exploit for Sparc Solaris RPC services" fullword ascii
condition:
( uint16(0) == 0x457f and filesize < 20KB and 1 of them ) or ( 2 of them )
}This YARA rule can be deployed in the following contexts:
This rule contains 4 string patterns in its detection logic.
Scenario: Scheduled System Maintenance Task
Description: A legitimate system maintenance task, such as schtasks.exe running a scheduled job to clean temporary files or update system caches, may trigger the rule due to the presence of the file ebbshave.v5.
Filter/Exclusion: Check the command line arguments and process tree. Exclude tasks with schtasks.exe and known maintenance scripts (e.g., cleanmgr.exe, defrag.exe).
Scenario: Antivirus or Endpoint Protection Scan
Description: A security tool like Malwarebytes or Kaspersky may scan for known malicious files, including ebbshave.v5, during a full system scan.
Filter/Exclusion: Filter by process name (mbam.exe, kavservice.exe) or check for known security tool signatures in the process tree.
Scenario: Legitimate File Access by System Services
Description: The file ebbshave.v5 may be accessed by system services like Windows Update or Task Scheduler during normal operations, especially if the file is mistakenly present on the system.
Filter/Exclusion: Exclude processes associated with system services (e.g., svchost.exe, wuauserv.exe) or filter by file access patterns (e.g., read-only access, no execution).
Scenario: File Integrity Monitoring (FIM) Tool Activity
Description: A FIM tool like Tripwire or OSSEC may trigger the rule when it detects changes to the file ebbshave.v5 during a baseline check or integrity scan.
Filter/Exclusion: Exclude processes associated with FIM tools (e.g., tripwire, ossecalertd) or filter based on the type of file access (e.g., read-only,