Browse Definitions:
Definition

command-and-control servers (C&C center)

This definition is part of our Essential Guide: How to attack DDoS threats with a solid defense plan
Contributor(s): Matthew Haughn

A command and control server (C&C server) is a computer that issues directives to digital devices that have been infected with rootkits or other types of malware, such as ransomware. C&C servers can be used to create powerful networks of infected devices capable of carrying out distributed denial-of-service (DDoS) attacks, stealing data, deleting data or encrypting data in order to carry out an extortion scheme. In the past, a C&C server was often under an attacker's physical control and could remain active for several years. Today, C&C servers generally have a short shelf life; they often reside in legitimate cloud services and use automated domain generation algorithms (DGAs) to make it more difficult for law enforcement and white hat malware hunters to locate them. 

A malicious network under a C&C server's control is called a botnet and the network nodes that belong to the botnet are sometimes referred to as zombies. In a traditional botnet, the bots are  infected with a Trojan horse and use Internet Relay Chat (IRC) to communicate with a central C&C server. These botnets were often used to distribute spam or malware and gather misappropriated information, such as credit card numbers. 

Popular botnet topologies include:

  • Star topology - the bots are organised around a central server.
  • Multi-server topology - there are multiple C&C servers for redundancy.
  • Hierarchical topology - multiple C&C servers are organized into tiered groups.
  • Random topology - coopted computers communicate as a peer-to-peer botnet (P2P botnet).

Since IRC communication was typically used to command botnets, it is often guarded against. This has motivated the drive for more covert ways for C&C servers to issue commands. Alternative channels used for botnet command include JPG images, Microsoft Word files and posts from LinkedIn or Twitter dummy accounts.

Learn more about botnet command and control in this video:

This was last updated in January 2017 ???publishDate.suggestedBy???

Continue Reading About command-and-control servers (C&C center)

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

SearchCloudProvider

  • cloud ecosystem

    A cloud ecosystem is a complex system of interdependent components that all work together to enable cloud services.

  • cloud services

    Cloud services is an umbrella term that may refer to a variety of resources provided over the internet, or to professional ...

  • uncloud (de-cloud)

    The term uncloud describes the action or process of removing applications and data from a cloud computing platform.

SearchSecurity

  • Common Body of Knowledge (CBK)

    In security, Common Body of Knowledge (CBK) is a comprehensive framework of all the relevant subjects a security professional ...

  • rootkit

    A rootkit is a program or, more often, a collection of software tools that gives a threat actor remote access to and control over...

  • Metamorphic virus

    A metamorphic virus is a type of malware that is capable of changing its code and signature patterns with each iteration.

SearchHealthIT

  • clinical trial

    A clinical trial, also known as a clinical research study, is a protocol to evaluate the effects and efficacy of experimental ...

  • Practice Fusion

    Practice Fusion Inc. is a San Francisco-based company that developed a free electronic health record (EHR) system available to ...

  • RHIA (Registered Health Information Administrator)

    An RHIA, or registered health information administrator, is a certified professional who oversees the creation and use of patient...

SearchDisasterRecovery

SearchStorage

  • Red Hat OpenStack Platform

    Red Hat OpenStack Platform is a commercially supported distribution of open source OpenStack software designed to build and ...

  • storage medium (storage media)

    In computers, a storage medium is any technology -- including devices and materials -- used to place, keep and retrieve ...

  • Random Access Memory (RAM)

    Random Access Memory (RAM) is the hardware in a computing device where the operating system (OS), application programs and data ...

SearchSolidStateStorage

  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.

Close