The hypothesis is that the detection rule identifies potential adversary activity involving the exfiltration of sensitive data through unauthorized file transfers in the Azure environment. SOC teams should proactively hunt for this behavior to identify and mitigate data leakage risks before they escalate into larger breaches.
YARA Rule
rule BlackEnergy_Driver_USBMDM
{
meta:
description = "Auto-generated rule - from files 7874a10e551377d50264da5906dc07ec31b173dee18867f88ea556ad70d8f094, b73777469f939c331cbc1c9ad703f973d55851f3ad09282ab5b3546befa5b54a, edb16d3ccd50fc8f0f77d0875bf50a629fa38e5ba1b8eeefd54468df97eba281"
author = "Florian Roth"
reference = "http://www.welivesecurity.com/2016/01/03/blackenergy-sshbeardoor-details-2015-attacks-ukrainian-news-media-electric-industry/"
date = "2016-01-04"
super_rule = 1
hash1 = "7874a10e551377d50264da5906dc07ec31b173dee18867f88ea556ad70d8f094"
hash2 = "b73777469f939c331cbc1c9ad703f973d55851f3ad09282ab5b3546befa5b54a"
hash3 = "edb16d3ccd50fc8f0f77d0875bf50a629fa38e5ba1b8eeefd54468df97eba281"
hash4 = "ac13b819379855af80ea3499e7fb645f1c96a4a6709792613917df4276c583fc"
hash5 = "7a393b3eadfc8938cbecf84ca630e56e37d8b3d23e084a12ea5a7955642db291"
hash6 = "405013e66b6f137f915738e5623228f36c74e362873310c5f2634ca2fda6fbc5"
hash7 = "244dd8018177ea5a92c70a7be94334fa457c1aab8a1c1ea51580d7da500c3ad5"
hash8 = "edcd1722fdc2c924382903b7e4580f9b77603110e497393c9947d45d311234bf"
strings:
$s1 = "USB MDM Driver" fullword wide
$s2 = "KdDebuggerNotPresent" fullword ascii /* Goodware String - occured 50 times */
$s3 = "KdDebuggerEnabled" fullword ascii /* Goodware String - occured 69 times */
condition:
uint16(0) == 0x5a4d and filesize < 180KB and all of them
}This YARA rule can be deployed in the following contexts:
This rule contains 3 string patterns in its detection logic.
Scenario: A system administrator is using PowerShell to automate the deployment of a new application, which involves creating and modifying files in the C:\Program Files\ directory.
Filter/Exclusion: Check for process.name = powershell.exe and process.args containing "deploy" or "install", or filter by process.user = Administrator and process.parent.name = task scheduler.
Scenario: A scheduled job runs nightly to clean up temporary files using Windows Task Scheduler and the del command, which may trigger file modification alerts.
Filter/Exclusion: Filter by process.name = cmd.exe and process.parent.name = schtasks.exe, or check for process.args containing "del" and "C:\Windows\Temp\*".
Scenario: A backup tool like Veeam or Commvault is performing a backup operation, which may involve copying files to a network share or local directory.
Filter/Exclusion: Use process.name = veeam.exe or commvault.exe, or check for process.args containing "backup" or "snapshot".
Scenario: A configuration management tool like Ansible or Chef is executing a playbook that modifies files on multiple servers, which could be flagged as suspicious activity.
Filter/Exclusion: Filter by process.name = ansible.exe or chef-client.exe, or check for process.args containing "playbook" or "inventory".
Scenario: A developer is using Git to push changes to a remote repository, which may involve file operations that trigger the detection rule.
Filter/Exclusion: Check for process.name = git.exe and `process.args