A Command and Control (C2 / C&C) Server is a centralized infrastructure used by threat actors to send instructions to systems compromised by malware, such as Infostealers, and to receive the data exfiltrated from those infected devices.
In the lifecycle of a cyberattack, the Command and Control (C2) Server acts as the brain of the entire operation. Once an Infostealer successfully infiltrates a target device, it relies on the C2 infrastructure to transmit harvested credentials, session tokens, and sensitive files back to the attacker.
The communication between the infected host and the C2 server is often stealthy and encrypted to avoid detection by firewalls. This relationship involves several key functions:
Neutralizing a C2 connection is one of the most effective ways to stop a data breach in progress. If the link to the Command and Control center is severed, the malware becomes isolated, preventing the stolen data from reaching the criminal’s hands. Dark Radar platforms proactively track the IP addresses and domains associated with C2 infrastructures to alert organizations of active infections within their perimeter.
Modern vulnerability assessments prioritize identifying C2 communication patterns. By analyzing where the malware is "talking" to, security teams can identify the specific threat actor group involved and understand the broader scope of the campaign.
In summary; Command and Control (C2) servers are the operational hubs for cybercrime. Identifying and blocking these servers is a critical step in dismantling complex infostealer operations and protecting organizational data.
Credential Stuffing is a cyberattack where stolen account credentials (usernames and passwords), often obtained from data breaches or Infostealer logs, are used to gain unauthorized access to other unrelated online services through automated login attempts.
A Credential Leak is the unauthorized exposure and distribution of sensitive login information, such as usernames, email addresses, and passwords. While a data breach often targets a database, Infostealers generate credential leaks by harvesting data directly from end-user devices, making the leaked information highly accurate and immediately actionable for attackers.
A Crypter is a software tool used by threat actors to encrypt, obfuscate, and hide a malicious stub to make it FUD (Fully Undetected) by security software such as Antivirus (AV), EDR, and XDR systems. It serves as a protective shell that prevents static analysis by altering the file's signature and structure while preserving its malicious functionality during execution.
