CISA updates advanced persistent threat advisory

On December 23, the Cybersecurity and Infrastructure Security Agency (CISA) updated its advisory on the Advanced Persistent Threat Compromise of Government Agencies, Critical Infrastructure, and Private Sector Organizations.

CISA is aware of compromises of U.S. government agencies, critical infrastructure entities, and private sector organizations by an advanced persistent threat (APT) actor beginning in at least March 2020. This APT actor has demonstrated patience, operational security, and complex tradecraft in these intrusions. CISA expects that removing this threat actor from compromised environments will be highly complex and challenging for organizations.

One of the initial access vectors for this activity is a supply chain compromise of the following SolarWinds Orion products (see Appendix A).

  • Orion Platform 2019.4 HF5, version 2019.4.5200.9083
  • Orion Platform 2020.2 RC1, version 2020.2.100.12219
  • Orion Platform 2020.2 RC2, version 2020.2.5200.12394
  • Orion Platform 2020.2, 2020.2 HF1, version 2020.2.5300.12432

Note (updated December 23, 2020): CISA has evidence that there are initial access vectors other than the SolarWinds Orion platform. Specifically, we are investigating incidents in which activity indicating abuse of Security Assertion Markup Language (SAML) tokens consistent with this adversary’s behavior is present, yet where impacted SolarWinds instances have not been identified. CISA is working to confirm initial access vectors and identify any changes to the TTPs. CISA will update this Alert as new information becomes available. Refer to for additional resources.

On December 13, 2020, CISA released Emergency Directive 21-01: Mitigate SolarWinds Orion Code Compromise, ordering federal civilian executive branch departments and agencies to disconnect affected devices. Note: this Activity Alert does not supersede the requirements of Emergency Directive 21-01 (ED-21-01) and does not represent formal guidance to federal agencies under ED 21-01.

CISA has determined that this threat poses a grave risk to the Federal Government and state, local, tribal, and territorial governments as well as critical infrastructure entities and other private sector organizations. CISA advises stakeholders to read this Alert and review the enclosed indicators (see Appendix B).

Full information is available here.

Source: CISA