Employ network appliances and endpoint software to filter ingress, egress, and lateral network traffic. This includes protocol-based filtering, enforcing firewall rules, and blocking or restricting traffic based on predefined conditions to limit adversary movement and data exfiltration. This mitigation can be implemented through the following measures: Ingress Traffic Filtering: - Use Case: Configure network firewalls to allow traffic only from authorized IP addresses to public-facing servers. - Implementation: Limit SSH (port 22) and RDP (port 3389) traffic to specific IP ranges. Egress Traffic Filtering: - Use Case: Use firewalls or endpoint security software to block unauthorized outbound traffic to prevent data exfiltration and command-and-control (C2) communications. - Implementation: Block outbound traffic to known malicious IPs or regions where communication is unexpected. Protoc…
MITRE mitigation sourceAvoid CAPTCHA
Adversaries may avoid CAPTCHA challenges by mimicking human behavior. Automation tests, such as CAPTCHA, are typically used by defenders to detect and prevent bot and spam traffic from accessing protected webpages. CAPTCHAs are often placed before login screens or form fields. Traditional CAPTCHAs ask the user to decipher a string of characters, type the characters into a box, and submit the form. reCAPTCHA asks the user to identify images, click a checkbox, or evaluate the user’s behavior from mouse movement and device cookies.(Citation: CAPTCHAS Cloudflare) Adversaries may attempt to avoid CAPTCHA challenges by constructing a bot that mimics human behavior through browser automation. The automated browser may mimic a human by [Masquerading](https://attack.mitre.org/techniques/T1036) a [Browser Fingerprint](https://attack.mitre.org/techniques/T1036/012) and through attributes such as session history, IP reputation, and the use of browser APIs.(Citation: CAPTCHA Bypass Olostep) For example, adversaries may use Selenium browsers to simulate a human user. In the Selenium browsers, JavaScript is injected into the website’s Document Object Model (DOM). The injected script may modify browser attributes such as Audio Context and Voice engines, graphic rendering, installed fonts, and browser navigator objects.(Citation: Sentinel CAPTCHA Bypass)
Open in the interactive knowledge mesh
Detection overview
Use the published detection strategies below and validate required telemetry in the target environment.
Observed groups
No current Enterprise group relationship is published in this bundle.
Attack tools, simulations and detection rules
Follow explicit source relationships into the reference modules. Linked procedures and detectors are not claims of live validation or actor attribution.
- T1696.002 Avoid CAPTCHA simulation — Exact active technique ID
- T1696.002 detection rules — Exact active technique ID; not actor-specific detector coverage
Cyber Knowledge context
Use these routes to move from the ATT&CK behavior into explanation, implementation, evidence handling, validation, and defensive operations. Relevance is generated from explicit identifiers/names and governed topic mappings; it is not attribution evidence.
Malware Analysis & Reverse Engineering · Tactic learning route · 24/100Module 4 — Detection engineering and detection as code
Blue Team & Defensive Security · Tactic learning route · 24/100Disk, file-system, and persistence forensics
Digital Forensics & Incident Response (DFIR) · Tactic learning route · 24/100
MITRE mitigations
Use intrusion detection signatures to block traffic at network boundaries.
MITRE mitigation sourceMITRE detection strategies and analytics
- AN2105 · Analytic 2105 — No target-side behavioral Detection Strategy exists for Avoid CAPTCHA based solely on CAPTCHA telemetry.