Complex sentence: On July 25,2016, the FBI announced that it would investigate the hack that security experts such as CrowdStrike, Fidelis Cybersecurity, Mandiant, SecureWorks, ThreatConnect, the editor for Ars Technica, and others believe was linked to the Russian government.
Split into simpler sentences: On July 25,2016, the FBI announced that it would investigate the hack. Security experts such as CrowdStrike, Fidelis Cybersecurity, Mandiant, SecureWorks, ThreatConnect, the editor for Ars Technica, and others believe was linked to the Russian government.