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Get Started Free →An adversary may deface systems external to an organization in an attempt to deliver messaging, intimidate, or otherwise mislead an organization or users.
.claude/skills/cyberstrikeus-t1491-002-external-defacement/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-07 | ✗→✓ | ▲ Improved | 24% | 0% |
| case-03 | ✗→✓ | ▲ Improved | 31% | 0% |
| case-09 | ✗→✓ | ▲ Improved | -59% | 0% |
| case-11 | ✗→✓ | ▲ Improved | -11% | 0% |
| case-12 | ✗→✓ | ▲ Improved | -32% | 0% |
> Sub-technique of: T1491
An adversary may deface systems external to an organization in an attempt to deliver messaging, intimidate, or otherwise mislead an organization or users. External Defacement may ultimately cause users to distrust the systems and to question/discredit the system’s integrity. Externally-facing websites are a common victim of defacement; often targeted by adversary and hacktivist groups in order to push a political message or spread propaganda. External Defacement may be used as a catalyst to trigger events, or as a response to actions taken by an organization or government. Similarly, website defacement may also be used as setup, or a precursor, for future attacks such as Drive-by Compromise.
Platforms: Windows, IaaS, Linux, macOS
> Note: No Atomic Red Team tests available for this technique. See Atomic Red Team GitHub for updates.
Consider implementing IT disaster recovery plans that contain procedures for taking regular data backups that can be used to restore organizational data. Ensure backups are stored off system and is protected from common methods adversaries may use to gain access and destroy the backups to prevent recovery.
| Finding | Severity | Impact | | ---------------------------------------- | -------- | ------ | | External Defacement technique applicable | Low | Impact |
| CWE ID | Title | | ------- | --------------------------------- | | CWE-400 | Uncontrolled Resource Consumption |
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-07 | fail→pass | 17,645 | 21,385 | +21% | 1 | 1 | 0% | 1,998 | 2,478 | +24% | 0 | 0 | — |
case-01 | fail→fail | 24,515 | 29,313 | +20% | 1 | 1 | 0% | 3,920 | 4,734 | +21% | 0 | 0 | — |
case-02 | fail→fail | 22,576 | 22,245 | -1% | 1 | 1 | 0% | 3,457 | 3,615 | +5% | 0 | 0 | — |
case-03 | fail→pass | 29,323 | 32,000 | +9% | 1 | 1 | 0% | 3,817 | 5,015 | +31% | 0 | 0 | — |
case-04 | pass→pass | 34,903 | 38,725 | +11% | 1 | 1 | 0% | 4,260 | 5,640 | +32% | 0 | 0 | — |
case-05 | pass→pass | 21,551 | 25,251 | +17% | 1 | 1 | 0% | 2,518 | 4,030 | +60% | 0 | 0 | — |
case-06 | pass→pass | 21,657 | 15,835 | -27% | 1 | 1 | 0% | 2,681 | 3,403 | +27% | 0 | 0 | — |
case-08 | fail→fail | 20,966 | 9,759 | -53% | 1 | 1 | 0% | 2,754 | 1,704 | -38% | 0 | 0 | — |
case-09 | fail→pass | 20,068 | 8,478 | -58% | 1 | 1 | 0% | 3,487 | 1,439 | -59% | 0 | 0 | — |
case-10 | pass→pass | 14,888 | 12,774 | -14% | 1 | 1 | 0% | 2,412 | 2,132 | -12% | 0 | 0 | — |
case-11 | fail→pass | 8,679 | 9,348 | +8% | 1 | 1 | 0% | 1,528 | 1,360 | -11% | 0 | 0 | — |
case-12 | fail→pass | 18,013 | 2,927 | -84% | 1 | 1 | 0% | 1,937 | 1,313 | -32% | 0 | 0 | — |
case-13 | fail→pass | 12,928 | 7,498 | -42% | 1 | 1 | 0% | 1,934 | 1,290 | -33% | 0 | 0 | — |
case-14 | fail→pass | 17,623 | 1,893 | -89% | 1 | 1 | 0% | 1,708 | 1,119 | -34% | 0 | 0 | — |
case-15 | fail→pass | 25,754 | 22,584 | -12% | 1 | 1 | 0% | 3,026 | 3,642 | +20% | 0 | 0 | — |
case-16 | fail→pass | 18,803 | 6,882 | -63% | 1 | 1 | 0% | 2,391 | 1,158 | -52% | 0 | 0 | — |
case-17 | pass→pass | 22,951 | 16,418 | -28% | 1 | 1 | 0% | 2,648 | 3,186 | +20% | 0 | 0 | — |
case-18 | pass→pass | 15,184 | 7,702 | -49% | 1 | 1 | 0% | 1,611 | 1,332 | -17% | 0 | 0 | — |
case-19 | fail→pass | 6,991 | 6,484 | -7% | 1 | 1 | 0% | 300 | 1,120 | +273% | 0 | 0 | — |
case-20 | fail→pass | 16,166 | 4,002 | -75% | 1 | 1 | 0% | 1,837 | 1,635 | -11% | 0 | 0 | — |
case-21 | pass→pass | 27,170 | 8,430 | -69% | 1 | 1 | 0% | 3,824 | 1,308 | -66% | 0 | 0 | — |
case-22 | pass→pass | 7,911 | 1,364 | -83% | 1 | 1 | 0% | 484 | 1,084 | +124% | 0 | 0 | — |
case-23 | fail→pass | 15,254 | 2,032 | -87% | 1 | 1 | 0% | 1,372 | 1,219 | -11% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 23 cases were attempted. The headline lift of +52 percentage points is the difference between those two pass rates over the 23 comparable cases.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.