Ensure automatic forwarding to external domains is blocked in outbound spam policies

VisokaNivo 1Automatskam365

Opis

Attackers who compromise a mailbox commonly add forwarding rules to exfiltrate mail. Prints the number of outbound spam filter policies whose AutoForwardingMode is not Off (expected 0). Requires an already-connected Exchange Online session: Install-Module ExchangeOnlineManagement; Connect-ExchangeOnline (View-Only Organization Management is sufficient). The audit throws if no session exists.

Kako se proverava

Metod provere: Komanda ljuske

shell

$ErrorActionPreference = 'Stop'; if (-not (Get-Command Get-ConnectionInformation -ErrorAction SilentlyContinue) -or -not (Get-ConnectionInformation)) { throw 'Not connected: run Connect-ExchangeOnline first' }; $bad = @(Get-HostedOutboundSpamFilterPolicy -ErrorAction Stop | Where-Object { "$($_.AutoForwardingMode)" -ne 'Off' }); $bad.Count

Očekivani izlaz: 0

Kako se ispravlja

Metod ispravke: Smernica ili zakrpa infrastrukture

Set-HostedOutboundSpamFilterPolicy -Identity Default -AutoForwardingMode Off (and for each custom policy). Allow approved exceptions with a dedicated policy scoped to specific senders.

Svojstva

Operativni sistemi: Bilo koji
Oznake: m365mail-flow
Referenca: CIS Microsoft 365 Foundations Benchmark v7.0.0 - Exchange Online Protection / Outbound spam policy - automatic forwarding (verify section number for your release)

Proverite ovaj računar

Pokrenite ovo na računaru za koji imate dozvolu za proveru. Skeniranje radi u režimu samo za čitanje.

shell

tmaegis scan --target m365