SAST, DAST, and PR security review are often grouped together, but they answer different questions.
SAST asks: does the code match a risky pattern?
DAST asks: does the running application behave unsafely?
PR security review asks: did this change introduce exploitable risk before it merges?
Teams need all three at different moments. The problem starts when one workflow is expected to cover every kind of vulnerability.
SAST: broad code coverage
Static Application Security Testing scans source code without running the application.
SAST is useful for:
- Known vulnerability categories.
- CI policy checks.
- Language and framework-specific rules.
- Secrets and unsafe APIs.
- Broad repository coverage.
SAST is weaker when the issue depends on product intent, multi-step auth flow, or whether a path is reachable by an attacker.
DAST: runtime behavior
Dynamic Application Security Testing probes a running application.
DAST is useful for:
- Runtime misconfiguration.
- Exposed endpoints.
- Authentication and session issues.
- Known web vulnerability classes.
- Validating behavior in a deployed environment.
DAST is weaker when the vulnerable path is hard to reach, requires specific business state, or lives in code that is not exposed in the tested environment.
PR security review: merge-time judgment
PR security review looks at the code change while the author and reviewers are still deciding whether to merge it.
It is useful for:
- Broken access control.
- Business logic flaws.
- Prompt injection and AI agent behavior.
- Risky dependency or GitHub Actions changes.
- IaC permissions and deployment risk.
- Explaining exactly what the author should fix.
This is where Hacktron Review fits. It reviews pull requests for exploitable vulnerabilities and posts findings inline in GitHub.
Comparison table
| Workflow | Best at | Weakness | Best timing |
|---|---|---|---|
| SAST | Known code patterns | Context and reachability | CI and periodic scans |
| DAST | Runtime behavior | Code paths that tests cannot reach | Staging and production-like environments |
| PR review | Exploitability in a code change | Needs repository context | Before merge |
What to use first
If your current issue is “we have no security coverage,” start with SAST and dependency scanning.
If your issue is “we find bugs too late,” add PR security review.
If your issue is “we need proof the running app is exploitable,” add DAST or whitebox validation.
Hacktron is strongest in the middle: it helps teams catch risky code before merge, then escalate high-risk paths into deeper validation when needed.