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Security

What is ISAC?

An ISAC (Information Sharing and Analysis Center) is a member organization where companies in one sector share threat information, alerts and defenses.

What is an ISAC?

An Information Sharing and Analysis Center (ISAC) is a trusted community, usually organized around one critical infrastructure sector, in which member organizations exchange information about the threats they face. Banks share with banks, hospitals with hospitals and utilities with utilities, because organizations in the same sector tend to be targeted by the same attackers using the same techniques. In the United States the model dates to Presidential Decision Directive 63 in 1998, which called on the private sector to set up sharing centers for critical infrastructure.

Examples of ISACs

  • FS-ISAC for banks, insurers and other financial services firms, with members worldwide
  • Health-ISAC for hospitals, health insurers, pharmaceutical and medical device companies
  • E-ISAC for the North American electricity industry, operated by NERC
  • MS-ISAC for U.S. state, local, tribal and territorial governments
  • Others for sectors such as automotive, aviation, information technology, retail, and research and education

The National Council of ISACs coordinates across the sector groups. Information sharing and analysis organizations (ISAOs) follow the same idea without being tied to one sector, for example a regional group of businesses.

What members get and give

Many ISACs charge membership fees, often tiered by organization size. Members receive sector-specific alerts and analysis, machine-readable indicator feeds that are often delivered as STIX over TAXII or through MISP, briefings on active campaigns, working groups and joint exercises. The value depends on members contributing as well as consuming. Submissions can often be made anonymously through the ISAC, so a hospital can warn its peers about a new intrusion pattern without announcing that it was the victim. Shared items carry Traffic Light Protocol labels, and community rules, usually backed by a membership agreement, limit what can be passed on.

A sharing example

A regional bank's SOC spots a phishing campaign that imitates a payment processor and uses a lookalike domain registered the day before. Within the hour it posts the sender addresses, the domain and the lure text to its ISAC, labeled TLP:AMBER. Other member banks load the indicators into their mail gateways before the campaign reaches them, and two reply that they saw the same domain from different sending IPs, which widens everyone's blocklist. No single bank would have seen the whole campaign alone.

ISAC vs. other intelligence sources

  • ISAC: two-way sharing among peers in one sector; high relevance, membership required.
  • Government source: agencies such as CISA publish advisories and run programs like Automated Indicator Sharing; authoritative, often published after an investigation.
  • Commercial feed: a vendor sells curated intelligence; broad, but one-way.
  • OSINT: free public sources; wide coverage, no vetting.
  • CERT or CSIRT: a team that handles incidents, nationally or inside one organization, rather than a membership community.

ISAC on the CompTIA Security+ exam

ISACs are one of the threat intelligence sources taught under SY0-801 objective 2.1, which covers where information about threats comes from and how it reaches the people who use it. The acronym is not on the SY0-801 acronym list, so learn what it stands for. Scenario wording such as "share threat information with other organizations in the same industry", "sector-specific alerts" or "peer institutions exchange indicators" points to an ISAC. Distractors include OSINT (public and one-way), a proprietary feed (bought from a vendor), vendor advisories (flaws in one company's products) and dark web monitoring (searching for your own data offered for sale).

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Related terms

OSINT

OSINT (open-source intelligence) is information gathered from publicly available sources, such as websites, social media, DNS records and job postings.

STIX

STIX (Structured Threat Information Expression) is an OASIS standard JSON language for describing threat intelligence, from indicators to threat actors.

threat feed

A threat feed is a continuous, usually machine-readable stream of threat data, such as malicious IPs, domains and file hashes, that security tools ingest.

threat intelligence

Threat intelligence is evidence-based information about attackers, their methods and infrastructure, put in context so defenders can act on it.

Traffic Light Protocol

The Traffic Light Protocol (TLP) is a FIRST standard that labels shared information RED, AMBER, GREEN or CLEAR to show how far recipients may pass it on.

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