There's a whole body of regulation around service providers to the U.S. Government making it an effective requirement to use this stuff, starting with the FedRAMP Authorization Act (https://www.congress.gov/117/bills/hr7776/BILLS-117hr7776enr...).

See also Section 4.2.4 of the FedRAMP Moderate Readiness Assessment Report (RAR) which can be found here: https://www.fedramp.gov/documents-templates/ as an example.

You cannot obtain an Authorization To Operate (ATO) unless you've satisfied the Assessor that you're in compliance.

PCI DSS v4.0 Requirements 5 and 6 speaks very broadly for anti-malware controls, which Crowdstrike provides as EDR, and cybersecurity (liability, ransomware, etc) insurance absolutely requires it from the questionnaires I’ve completed and am required to attest to.

> In its first version, PCI DSS included controls for detecting, removing, blocking, and containing malicious code (malware). Until version 3.2.1, these controls were generically referred to as "anti-virus software", which was incorrect technically because they protect not just against viruses, but also against other known malware variants (worms, trojans, ransomware, spyware, rootkits, adware, backdoors, etc.). As a result, the term "antimalware" is now used not only to refer to viruses, but also to all other types of malicious code, more in line with the requirement's objectives.

> To avoid the ambiguities seen in previous versions of the standard about which operating systems should have an anti-malware solution installed and which should not, a more operational approach has been chosen: the entity should perform a periodic assessment to determine which system components should require an anti-malware solution. All other assets that are determined not to be affected by malware should be included in a list (req. 5.2.3).

> Updates of the anti-malware solution must be performed automatically (req. 5.3.1).

> Finally, the term "real-time scanning" is explicitly included for the anti-malware solution (this is a type of persistent, continuous scanning where a scan for security risks is performed every time a file is received, opened, downloaded, copied or modified). Previously, there was a reference to the fact that anti-malware mechanisms should be actively running, which gave rise to different interpretations.

> Continuous behavioral analysis of systems or processes is incorporated as an accepted anti-malware solution scanning method, as an alternative to traditional periodic (scheduled and on-demand) and real-time (on-access) scans (req. 5.3.2).

https://www.advantio.com/blog/analysis-of-pci-dss-v4.0-part-...

Besides things like FedRAMP mentioned in other comments, some large enterprise customers, especially banks, require terms in the contract stating the vendor uses some form of anti-malware software.