T0822 External Remote Services — Detection Rules

Source-backed rule directory

No reviewed association in this snapshot.

Atlas deterministic concepts

No exact concept selected.

Anomaly models

No exact Atlas model in this snapshot.

ATT&CK analytic guidance

DET0803 Detection of External Remote Services

AN1935 Analytic 1935

Real-time monitoring identifies authentication to an external remote access gateway using credentials associated with Industrial Control System (ICS)-role accounts, from a source geolocation or Autonomous System Number (ASN) inconsistent with the account's established usage pattern, immediately followed by that session establishing connectivity into the ICS network zone. Documented in VPNFilter, which specifically targeted routers and network edge devices. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.

AN2224 Analytic 2224

Near-real-time connection monitoring identifies connections to Industrial Control System (ICS) field device management ports from Internet Protocol (IP) addresses routed through external remote access infrastructure rather than from within the expected ICS network segments. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows. This analytic is implementable from session/flow metadata (endpoints, ports, protocol/service, timing, bytes); it does not require or claim packet-payload visibility.

AN2257 Analytic 2257

Real-time monitoring identifies an SSH authentication/session to an ICS Linux asset from a VPN-assigned or remote-access source outside the approved remote-administration baseline. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.

AN2265 Analytic 2265

Real-time monitoring identifies an Industrial Control System (ICS)-role account session originating from a Virtual Private Network (VPN)/remote access connection that subsequently accesses Windows ICS hosts in a pattern inconsistent with documented vendor support session profiles. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.