Windows Error Reporting Service Elevation of Privilege Vulnerability

• WinEvent Scheduled Task Created to Spawn Shell :
  endpoint Endpoint None version:20
  The following analytic detects the creation of scheduled tasks designed to execute commands using native Windows shells like PowerShell, Cmd, Wscript, or Cscript. It leverages Windows Security EventCode 4698 to identify when such tasks are registered. This activity is significant as it may indicate an attempt to establish persistence or execute malicious commands on a system. If confirmed malicious, this could allow an attacker to maintain access, execute arbitrary code, or escalate privileges, posing a severe threat to the environment.


• Windows App Layer Protocol Wermgr Connect To NamedPipe :
  endpoint Endpoint None version:11
  The following analytic detects the wermgr.exe process creating or connecting to a named pipe. It leverages Sysmon EventCodes 17 and 18 to identify these actions. This activity is significant because wermgr.exe, a legitimate Windows OS Problem Reporting application, is often abused by malware such as Trickbot and Qakbot to execute malicious code. If confirmed malicious, this behavior could indicate that an attacker has injected code into wermgr.exe, potentially allowing them to communicate covertly, escalate privileges, or persist within the environment.


• Windows Process Injection Wermgr Child Process :
  endpoint Endpoint None version:12
  The following analytic identifies a suspicious instance of wermgr.exe spawning a child process unrelated to error or fault handling. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process relationships and command-line executions. This activity is significant as it can indicate Qakbot malware, which injects malicious code into wermgr.exe to evade detection and execute malicious actions. If confirmed malicious, this behavior could allow an attacker to conduct reconnaissance, execute arbitrary code, and persist within the network, posing a severe security risk.


• System Processes Run From Unexpected Locations :
  endpoint Endpoint None version:17
  The following analytic identifies system processes running from unexpected locations outside of paths such as `C:\Windows\System32\` or `C:\Windows\SysWOW64`. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths, names, and hashes. This activity is significant as it may indicate a malicious process attempting to masquerade as a legitimate system process. If confirmed malicious, this behavior could allow an attacker to execute code, escalate privileges, or maintain persistence within the environment, posing a significant security risk.


• Windows Error Report Created in ReportQueue Manually :
  endpoint Endpoint None version:1
  The following analytic detects a .wer file being written into the Windows Error Reporting ReportQueue directory by a process other than the standard error-reporting binaries. Windows Error Reporting normally populates ReportQueue only through werfault.exe, werfaultsecure.exe, or wermgr.exe following an actual application crash. In the ShieldBreak exploit, the attacker fabricates a .wer report directly and manually invokes the QueueReporting scheduled task, which causes wermgr.exe to process the report and load an attacker-planted phantom DLL at SYSTEM integrity. If confirmed malicious, this activity indicates preparation for a local privilege escalation attempt abusing Windows Error Reporting.


• Windows Wermgr Spawning System Integrity Process :
  endpoint Endpoint None version:1
  The following analytic detects WerMgr.exe (Windows Error Reporting) spawning a child process running at SYSTEM integrity level. WerMgr.exe normally runs at the integrity level of the reporting user or as a background SYSTEM-owned service that does not launch interactive children. In the ShieldBreak exploit, WerMgr.exe is manually triggered via the QueueReporting scheduled task and loads an attacker-planted phantom DLL (phoneinfo.dll), which then spawns an elevated shell. If confirmed malicious, this activity indicates successful local privilege escalation to SYSTEM.