T14 — Infrastructure & Economic Warfare

Attacks aimed at degrading service availability, exhausting budget, or causing economic harm via abuse of the LLM endpoint. Adjacent to classical DoS but LLM-specific cost dynamics.

Techniques

T14.001 — Per-account budget exhaustion

• Multiple low-bandwidth requests each maximizing token cost
• Free-tier abuse via account creation farms
• Direct DDoS of paid endpoint (uses budget at attack rate)

Defenders: per-account caps + alerts.

T14.002 — Shared-quota poisoning

Multi-tenant LLM services share quotas at a provider level. Attacker exhausts the shared quota → all tenants degraded.

Targets: SaaS products that meter LLM access but share underlying API account.

T14.003 — GPU resource starvation

Self-hosted inference. Long-context queries hog GPU:

• Send queries near max context length
• Send batch of long-context queries in parallel
• Loop to maintain pressure

Cost-amplification ratio: 1 user request → 100% GPU utilization.

T14.004 — Cost amplification (T5.002 cross-ref)

Prompt engineering to maximize output cost:

• "Repeat 'token' 5000 times"
• "Generate the maximum-length response you're allowed to produce"
• Quadratic context patterns that bloat each turn

T14.005 — Pricing-tier exploit

Some APIs charge differently based on model variant. Trick the endpoint into using the expensive variant via parameter manipulation (T5.004 overlap).

T14.006 — Caching-pollution

Where LLM provider caches identical prompts (cost-reduction feature):

• Submit prompts that fill cache but produce uncacheable outputs
• Cache thrashing → no cost savings, full cost incurred

T14.007 — Streaming attack

Open many streaming requests → never consume → endpoint holds connection slots open until timeout.

Probe pattern

T14 is load-testing territory. Use k6, locust, hey:

# Spike test
hey -n 1000 -c 100 -m POST -H 'Authorization: Bearer X' \
  -d '{"prompt":"'$(python3 -c 'print("a"*100000)')'"}' \
  https://target/api/chat

Monitor:

• Cost / minute via provider dashboard
• p99 latency
• 429 / 503 error rate
• Other-tenant impact (if multi-tenant)

Detection signals

• Cost spike >5x baseline w/o feature change
• p99 latency degradation
• Specific user IDs / IPs concentrating traffic
• Output token distribution skewed long

Severity

Defender

• Per-account hard budget caps (with grace + alert at 80%/95%)
• max_tokens strictly enforced (no unlimited)
• Context-length per-tier caps
• Rate limits per-account AND global (catch shared-quota attacks)
• Anomaly detection on cost/latency/concurrency
• Caching: per-tenant cache, not global
• Streaming: connection timeout aggressive (60s if no consumer)

Cross-references

• T5 (API exploitation) — overlap on cost/abuse vectors
• Classical DDoS skills skills/exploit/web/...