T1695: Block Communications
Operational technology communications occur over serial COM, Ethernet, Wi-Fi, cellular (4G/5G), and satellite mediums. Adversaries may block communications to prevent reporting messages and command messages from reaching their intended target devices disrupting processes, operations, and causing cyber-physical impacts.[1]
Adversaries may block communications by either making modifications to software (System Firmware, Module Firmware, Hooking, and Rootkit) and services (Service Stop, Denial of Service) on systems and devices or by positioning themselves between systems and devices and intercepting and blocking the communications such as the case with an Adversary-in-the-Middle attack.
Security context for executives and security teams
T1695: Block Communications describes Operational technology communications occur over serial COM, Ethernet, Wi-Fi, cellular (4G/5G), and satellite mediums. Adversaries may block communications to prevent reporting messages and command messages from reaching their intended target devices disrupting processes, operations, and causing cyber-physical impacts.(Citation: Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011) Adversaries may block communications by either making modifications to software ([System Firmware](https://attack.mitre.org/techniques/T0857...
Executive priority
T1695: Block Communications is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.
Technical view
Security teams should validate T1695: Block Communications by reviewing the official ATT&CK relationships, mapped tactics (inhibit-response-function), supported platforms (Embedded, Windows, Linux, Network Devices), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether T1695: Block Communications appears in your detection coverage and tabletop scenarios.
- Use the object to align executive risk language with SOC, incident response, and detection engineering work.
- Do not treat ATT&CK relationship context as attribution without corroborating evidence.
Mitigation priorities
- Map the object to existing controls and identify missing telemetry or response ownership.
- Prioritize mitigations that reduce exposure on the listed platforms and tactics.
- Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits
Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.
This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Block Communications
Operational technology communications occur over serial COM, Ethernet, Wi-Fi, cellular (4G/5G), and satellite mediums. Adversaries may block communications to prevent reporting messages and command messages from reaching their intended target devices disrupting processes, operations, and causing cyber-physical impacts.[1]
Adversaries may block communications by either making modifications to software (System Firmware, Module Firmware, Hooking, and Rootkit) and services (Service Stop, Denial of Service) on systems and devices or by positioning themselves between systems and devices and intercepting and blocking the communications such as the case with an Adversary-in-the-Middle attack.
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Related techniques
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
Groups, software, and campaigns
G1027: CyberAv3ngers
The CyberAv3ngers are a suspected Iranian Government Islamic Revolutionary Guard Corps (IRGC)-affiliated APT group. The CyberAv3ngers have been known to be active since at least 2020, with disputed and false claims of critical infrastructure compromises in Israel.[1]
In 2023, the CyberAv3ngers engaged in a global targeting and hacking of the Unitronics Programmable Logic Controller (PLC) with Human-Machine Interface (HMI). This PLC can be found in multiple sectors, including water and wastewater, energy, food and beverage manufacturing, and healthcare. The most notable feature of this attack was the defacement of the devices user interface.[1]
All related ATT&CK context
Mitigation direction
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.
Imported snapshots across ATT&CK releases(3)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 20.0 | 1.0 | Current bundle | c3f6944120d9… | ||
| 19.2 | 1.0 | Older bundle | cfdd18aff715… | ||
| 19.1 | 1.0 | Older bundle | cfdd18aff715… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011
Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011 A Taxonomy of Cyber Attacks on SCADA Systems Retrieved. 2018/01/12
- [2]mitre-attackT1695Open source URL
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