ORCA.109: Senders are not being allow listed in an unsafe manner.
| ID | ORCA.109 |
| Severity | Medium |
| Suite | ORCA |
| Product | Defender |
| Related products | Exchange Online |
| Feature | Anti-spam |
| Security area | Email and collaboration protection |
| Resource type | Policy |
| User impact of fixing | Low |
| Effort to fix | Medium |
| Framework controls | nist-800-53-r5:SI-8 Spam Protection |
| MITRE ATT&CK | T1566, T1684.002 |
| Reads from | Exchange Online |
What this checks and how to fix it
Section titled “What this checks and how to fix it”Emails coming from allow listed senders bypass several layers of protection within Exchange Online Protection. If senders are allow listed, they are open to being spoofed from malicious actors.
Remediation action
Section titled “Remediation action”Remove allow listing on senders.
Related Links
Section titled “Related Links”- Microsoft 365 Defender Portal - Anti-spam settings
- Recommended settings for EOP and Office 365 Microsoft Defender for Office 365 security
- Use Anti-Spam Policy Sender/Domain Allow lists
Mito check, based on ORCA. Author: soulemike. Open-source licences.
Open-source licences. CIS Benchmark material © Center for Internet Security, Inc.; CISA SCuBA baselines are public domain (CC0).
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