The detection identifies potential Wild Neutron APT activity through suspicious file behavior indicative of adversary persistence and lateral movement. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate advanced persistent threats before they escalate.
YARA Rule
rule WildNeutron_Sample_8
{
meta:
description = "Wild Neutron APT Sample Rule - file 758e6b519f6c0931ff93542b767524fc1eab589feb5cfc3854c77842f9785c92"
author = "Florian Roth"
reference = "https://securelist.com/blog/research/71275/wild-neutron-economic-espionage-threat-actor-returns-with-new-tricks/"
date = "2015-07-10"
score = 60
hash = "758e6b519f6c0931ff93542b767524fc1eab589feb5cfc3854c77842f9785c92"
strings:
$x1 = "RunFile: couldn't load SHELL32.DLL!" fullword ascii /* PEStudio Blacklist: strings */ /* score: '27.00' */
$x2 = "RunFile: couldn't find ShellExecuteExA/W in SHELL32.DLL!" fullword ascii /* PEStudio Blacklist: strings */ /* score: '35.00' */
$x3 = "Error executing CreateProcess()!!" fullword wide /* PEStudio Blacklist: strings */ /* score: '31.00' */
$x4 = "cmdcmdline" fullword wide /* score: '11.00' */
$x5 = "Invalid input handle!!!" fullword ascii /* PEStudio Blacklist: strings */ /* score: '10.00' */
$s1 = "Process %d terminated" fullword wide /* PEStudio Blacklist: strings */ /* score: '24.00' */
$s2 = "Process is not running any more" fullword wide /* PEStudio Blacklist: strings */ /* score: '22.00' */
$s3 = "javacpl.exe" fullword wide /* score: '3.00' */ /* Goodware String - occured 2 times */
$s4 = "Windows NT Version %lu.%lu" fullword wide /* PEStudio Blacklist: os */ /* score: '19.00' */
$s5 = "Usage: destination [reference]" fullword wide /* PEStudio Blacklist: strings */ /* score: '16.00' */
$s6 = ".com;.exe;.bat;.cmd" fullword wide /* score: '15.00' */
$s7 = ") -%s-> %s (" fullword ascii /* score: '14.00' */
$s8 = "cmdextversion" fullword wide /* score: '14.00' */
$s9 = "Invalid pid (%s)" fullword wide /* PEStudio Blacklist: strings */ /* score: '13.00' */
$s10 = "\"%s\" /K %s" fullword wide /* score: '11.02' */
$s11 = "Error setting %s (%s)" fullword wide /* score: '11.00' */
$s12 = "DEBUG: Cannot allocate memory for ptrNextNode->ptrNext!" fullword ascii /* PEStudio Blacklist: strings */ /* score: '10.00' */
$s13 = "Failed to build full directory path" fullword wide /* score: '10.00' */
$s14 = "DEBUG: Cannot allocate memory for ptrFileArray!" fullword ascii /* PEStudio Blacklist: strings */ /* score: '9.00' */
$s15 = "%-8s %-3s %*s %s %s" fullword wide /* score: '8.00' */
$s16 = " %%%c in (%s) do " fullword wide /* score: '8.00' */
condition:
uint16(0) == 0x5a4d and filesize < 1677KB and 2 of ($x*) and 6 of ($s*)
}This YARA rule can be deployed in the following contexts:
This rule contains 21 string patterns in its detection logic.
Scenario: Legitimate Software Update via Chocolatey
Description: A legitimate software update is being installed via Chocolatey, which matches the hash of a known Wild Neutron APT sample.
Filter/Exclusion: process.name != "choco.exe" OR process.parent.name != "chocolatey.exe" OR file.hash != "758e6b519f6c0931ff93542b767524fc1eab589feb5cfc3854c77842f9785c92"
Scenario: Scheduled System Maintenance Task
Description: A scheduled task is running a script or executable that matches the Wild Neutron hash, but it is part of a routine system maintenance or patching process.
Filter/Exclusion: process.name != "schtasks.exe" OR process.parent.name != "taskhost.exe" OR file.hash != "758e6b519f6c0931ff93542b767524fc1eab589feb5cfc3854c77842f9785c92"
Scenario: Admin Task Using PowerShell for Configuration
Description: An administrator is using PowerShell to configure system settings, and the script or module being executed matches the Wild Neutron hash.
Filter/Exclusion: process.name != "powershell.exe" OR process.parent.name != "explorer.exe" OR `file.hash != “758e6b519f6c0931ff93542b767524fc1eab589feb5cfc3854c77842f