Taking advantage of VPN vulnerabilities within hours after they had been announced publicly, Iranian government-backed hacking groups have been setting up secret backdoors in various countries around the world since 2019. ZDNet reported that the targeted companies consisted of the IT, telecommunications, oil & gas, aviation, government, and security industries. The compromised VPNs, all of which are enterprise-grade, include Pulse Secure, Palo Alto Networks, Fortinet, and Citrix.