Threat Spotlight: Group 72, Opening the ZxShell
ZxShell has been observed to be distributed through phishing attacks, dropped by exploits that leverage vulnerabilities such as CVE-2011-2462, CVE-2013-3163, and CVE-2014-0322.
CVE-2013-3163 KEVPublic exploitEnd of life High · 8.8 EPSS 70.7%
Microsoft Internet Explorer Memory Corruption Vulnerability
Microsoft · Internet Explorer
End of lifeInternet Explorer reached End of lifeThe vendor no longer ships security fixes. Remove or isolate the product instead of waiting for a patch. on 15 Jun 2022. No patch is coming: remove or isolate it.
Summary
The flaw is a memory corruption vulnerability in Microsoft Internet Explorer, affecting versions 8 through 10. An attacker who lures a user to a crafted web site can execute arbitrary code or cause a denial of service, and this requires no prior authentication but does require the user to visit the malicious page over the network.
Official description · NVD
Microsoft Internet Explorer 8 through 10 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Internet Explorer Memory Corruption Vulnerability," a different vulnerability than CVE-2013-3144 and CVE-2013-3151.
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
57.9 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 1
- Tactics
- 2/15
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 16 months after disclosure. Public exploit code (Metasploit) was available 1 day before disclosure.
- Public exploit codeMetasploit1 day before
- Disclosedday 0
- Added to CISA KEVEU database agrees+10 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, 2 cited passages 11Initial AccessTA0001
Drive-by Compromise T1189 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
Drive-by via malicious website browsing
via a crafted web site
ExecutionTA0002
Exploitation for Client Execution T1203 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.
MITRE CTID mapping of the CVE · uncategorised
Detection
0 rules for this CVE · 38 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-2013-3163 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.
Drive-by CompromiseT11893 general rules
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
Named in 1 threat report1 reportCiscoOct 2014
Reports are matched by finding the exact id CVE-2013-3163 in their text; nobody has reviewed the match. One passage is shown per report, at most 320 characters, linked to the original.
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