Microsoft Malware Protection Engine Improper Restriction of Operations Vulnerability
Microsoft · Malware Protection Engine
The Microsoft Malware Protection Engine, which runs within Microsoft Defender and Forefront on supported Windows versions and Windows Server and on Microsoft Exchange Server 2013 and 2016, fails to properly scan specially crafted files, resulting in memory corruption. An attacker can exploit this by getting a user to interact with a malicious file, which requires local access and user interaction, with no authentication needed.
The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to memory corruption. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability", a different vulnerability than CVE-2017-8538 and CVE-2017-8541.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 1/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 5 years after disclosure. Public exploit code (Exploit-DB) appeared 4 days after disclosure.
- Disclosedday 0
- Public exploit codeExploit-DB+4 days
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
3 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 3 cited passages 3ExecutionTA0002
Explicitly described as remote code execution
aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability
Memory corruption yields code execution in engine
does not properly scan a specially crafted file leading to memory corruption
User opens crafted file triggering the scanner
does not properly scan a specially crafted file leading to memory corruption
Detection
0 rules for this CVE · 169 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2017-8540 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Malicious FileT1204.00239 general rules
- Droppers Exploiting CVE-2017-11882criticalstable
- Ursnif Malware C2 URL Patterncriticalstable
- Exploit for CVE-2017-8759criticaltest
- Potential Maze Ransomware Activitycriticaltest
- File With Uncommon Extension Created By An Office Applicationhightest
- Flash Player Update from Suspicious Locationhightest
- GAC DLL Loaded Via Office Applicationshightest
- HackTool - LittleCorporal Generated Maldoc Injectionhightest
Command and Scripting InterpreterT105995 general rules
- HackTool - Sliver C2 Implant Activity Patterncriticaltest
- Lazarus Group Activitycriticaltest
- REvil Kaseya Incident Malware Patternscriticaltest
- Turla Group Lateral Movementcriticaltest
- Windows Defender AMSI Trigger Detectedhighstable
- Windows Defender Threat Detectedhighstable
- Abusable DLL Potential Sideloading From Suspicious Locationhightest
- Add Insecure Download Source To Wingethightest
Exploitation for Client ExecutionT120335 general rules
- Antivirus - Exploitation Framework Signaturecriticalstable
- Droppers Exploiting CVE-2017-11882criticalstable
- Audit CVE Eventcriticaltest
- CVE-2021-31979 CVE-2021-33771 Exploitscriticaltest
- CVE-2021-31979 CVE-2021-33771 Exploits by Sourgumcriticaltest
- Exploit for CVE-2017-8759criticaltest
- Antivirus - APT Malware Signaturecriticalexperimental
- Antivirus - Remote Access Tools Signaturecriticalexperimental
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX