MSTIC has observed NICKEL actors using exploits against unpatched systems to compromise remote access services and appliances. Upon successful intrusion, they have used credential dumpers or stealers to obtain legitimate credentials, which they used to gain access to victim accounts. NICKEL actors created and deployed custom malware that allowed them to maintain persistence on victim networks over extended periods of time. MSTIC has also observed NICKEL perform frequent and scheduled data collection and exfiltration from victim networks