Leviathan: Geostrategy and TTP (Tactics, Techniques and Procedures)
Mentions the CVE; no further detail.
CVE-2017-8759 KEVPublic exploit High · 7.8 EPSS 88.7%
Microsoft .NET Framework Remote Code Execution Vulnerability
Microsoft · .NET Framework
Summary
The Microsoft .NET Framework (versions 2.0 through 4.7, including 3.5, 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2 and 4.7) contains a flaw in how it handles code generation and input validation that allows code execution. An attacker can run arbitrary code on the affected system by getting a user to open a malicious document or application, requiring local access and user interaction but no prior authentication.
Official description · NVD
Microsoft .NET Framework 2.0, 3.5, 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2 and 4.7 allow an attacker to execute code remotely via a malicious document or application, aka ".NET Framework Remote Code Execution Vulnerability."
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
77.4 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 4
- 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.How attackers get in
What they do
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 1 day before it was disclosed. Public exploit code (Exploit-DB) was available the same day.
- First seen exploitedVulnCheck KEV evidence1 day before
- First dated threat reportproofpoint.com+33 days
- Added to CISA KEVEU database agrees+4 yrs
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
2 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, 5 cited passages 2ExecutionTA0002
Command and Scripting Interpreter T1059 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details.
AI mapping from the description · primary impact
direct remote code execution impact
allow an attacker to execute code remotely
Malicious File T1204.002 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details.
AI mapping from the description · how it is exploited
user opens malicious document or application
execute code remotely via a malicious document or application
Lower-confidence links (2)
These come from early or generic mappings, text matching, or contradict this CVE’s details (for example a public-facing technique on a bug that needs a user to open a file). Shown for completeness.
- Exploitation for Client ExecutionT1203 CTID attack_to_cve Phase 1 "Uncategorized" mapping (not staged by impact)
- PhishingT1566 CTID attack_to_cve Phase 1 "Uncategorized" mapping (not staged by impact)
Detection
1 rule for this CVE · 134 general rules for its techniquesRules for this CVE
1Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2017-8759 directly.- Exploit for CVE-2017-8759criticaltest
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
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Named in 4 threat reports4 reportsProofpoint2Lab52 / S2 GrupoTrend MicroOct 2017 – May 2019 · 1 undated
Reports are matched by finding the exact id CVE-2017-8759 in their text; nobody has reviewed the match. One passage is shown per report, at most 320 characters, linked to the original.
Cobalt Strikes Again, Spam Runs Target Russian Banks
…server, which is actually a backdoor Some of the backdoor’s commands are: d&exec — download and execute PE file more_eggs — download additional scripts gtfo — delete files/startup entries and terminate more_onion — run additional script more_power — run command shell commands Infection Chain via CVE-2017-8759…
5 passages name itOriginal (opens in a new tab) ↗
Leviathan: Espionage Actor Targets Defense & Government
Exploitation: Microsoft Excel and Word documents with macros (sometimes password-protected), very recent vulnerabilities such as CVE-2017-0199 and CVE-2017-8759, and malicious Microsoft Publisher files…
4 passages name itOriginal (opens in a new tab) ↗
2020 Financial Services and Insurance Industry Threat Report
CVE-2017-11882 JavaJavaScript CAPTCHA CVE-2018-8174 Compiled HTML File Autolt HTA Packager Shell Object IP Filtering Certutil CVE-2017-8570 Application Access Token Shortcut Fallout Exploit Kit CVE-2018-0802 Headers fencing XL4 macros CVE-2017-0199 CVE-2017-8759Lotus-Blue Toolkit (O365) Template Injection…
2 passages name itOriginal (opens in a new tab) ↗
Also 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