C2 Networks: The Invisible Threat in Your Infrastructure
DOI:
https://doi.org/10.32628/CSEIT25111794Abstract
C2 networks are a really important threat that often gets missed in today's companies. Attackers can use them to stick around, steal data, and plan other bad stuff without anyone noticing. This paper looks closely at C2 setups, how they've changed from simple central systems to trickier hidden channels that use encryption, DNS tunneling, and regular cloud services. We check out popular C2 tools like Cobalt Strike, Empire, Sliver, and Mythic, explaining how they work and avoid detection. We also explore ways to spot them, comparing old-school signature-based methods with newer anomaly-based and machine learning ways to find sneaky C2 communication. To back up what we talk about, we built a lab to copy real-world C2 situations, capturing and studying network traffic to find things that help in detection. The findings show that normal intrusion detection systems aren't great at catching encrypted C2 channels, which stresses using advanced behavioral and AI ways to detect them. This research helps to understand C2 network threats better and gives useful tips for cybersecurity folks to improve company defenses against these hidden but common threats.
📊 Article Downloads
References
Kharraz, A., Robertson, W., Balzarotti, D., Bilge, L., & Kirda, E. (2015). Cutting the Gordian Knot: A Look Under the Hood of Ransomware Attacks. DIMVA. https://doi.org/10.1007/978-3-319-20550-2_4 DOI: https://doi.org/10.1007/978-3-319-20550-2_1
CISA. (2021). Ransomware Guidance and Resources. Cybersecurity & Infrastructure Security Agency. https://www.cisa.gov/stopransomware
MITRE. (2024). Command and Control - Enterprise. MITRE ATT&CK Framework. https://attack.mitre.org/tactics/TA0011/
Symantec. (2019). The Evolution of C2 Communications. Symantec Enterprise Blogs. https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/evolution-c2-communications
National Institute of Standards and Technology (NIST). (2018). Guide to Malware Incident Prevention and Handling for Desktops and Laptops. SP 800-83 Rev.1. https://doi.org/10.6028/NIST.SP.800-83r1 DOI: https://doi.org/10.6028/NIST.SP.800-83r1
FireEye. (2013). Command and Control in the Fifth Domain. https://www.fireeye.com/content/dam/fireeye-www/services/pdfs/wp-command-and-control-in-the-fifth-domain.pdf
Palo Alto Networks Unit42. (2021). Ransomware Threat Report. https://unit42.paloaltonetworks.com/ransomware-threat-report-2021/
IBM X-Force. (2022). Cost of a Data Breach Report. https://www.ibm.com/reports/data-breach DOI: https://doi.org/10.12968/S1353-4858(22)70049-9
FBI IC3. (2024). Internet Crime Report 2023. https://www.ic3.gov/Media/PDF/AnnualReport/2023_IC3Report.pdf
Scarfone, K., & Mell, P. (2007). Guide to Intrusion Detection and Prevention Systems (IDPS). NIST Special Publication 800-94. https://doi.org/10.6028/NIST.SP.800-94 DOI: https://doi.org/10.6028/NIST.SP.800-94
SANS Institute. (2017). Command and Control Overview. https://www.sans.org/white-papers/command-and-control-overview/
Shackleford, D. (2013). Advanced Malware: Detection, Analysis and Prevention. SANS Analyst Program. https://www.sans.org/reading-room/whitepapers/malicious/advanced-malware-detection-analysis-prevention-34262
Trend Micro. (2018). Command and Control (C&C) Server. https://www.trendmicro.com/vinfo/us/security/definition/command-and-control-server
Verizon. (2024). Data Breach Investigations Report. https://www.verizon.com/business/resources/reports/dbir/
Caltagirone, S., Pendergast, A., & Betz, C. (2013). The Diamond Model of Intrusion Analysis. https://www.activeresponse.org/wp-content/uploads/2013/07/diamond.pdf
Hutchins, E. M., Cloppert, M. J., & Amin, R. M. (2011). Intelligence-Driven Computer Network Defense Informed by Analysis of Adversary Campaigns and Intrusion Kill Chains. https://www.lockheedmartin.com/content/dam/lockheed-martin/rms/documents/cyber/LM-White-Paper-Intel-Driven-Defense.pdf
FireEye. (2020). APT41: Double Dragon. https://www.fireeye.com/current-threats/apt-groups.html
Cisco Talos. (2019). DNS as a Covert Channel Within Malware. https://blog.talosintelligence.com/2019/09/dns-tunneling.html
Proofpoint. (2021). Threat Actor Use of Cloud Services for C2. https://www.proofpoint.com/us/blog/threat-insight/threat-actors-leverage-cloud
Mandiant. (2022). M-Trends 2022: Cybersecurity Trends and Insights. https://www.mandiant.com/resources/m-trends
Stewart, J. (2010). Botnets: The Killer Web App. Syngress.
Bailey, M., Cooke, E., Jahanian, F., Watson, D., & Nazario, J. (2009). The Blended Threat of Bots and Botnets. Communications of the ACM, 50(11), 101-107. https://doi.org/10.1145/1409360.1409382 DOI: https://doi.org/10.1145/1409360.1409382
Symantec. (2019). The Evolution of C2 Communications. https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/evolution-c2-communications
Porras, P. A., Saidi, H., & Yegneswaran, V. (2014). A Foray into Conficker’s Logic and Rendezvous Points. In USENIX LEET. https://www.usenix.org/legacy/event/leet09/tech/full_papers/porras/porras.pdf
Mandiant. (2022). M-Trends 2022: Cybersecurity Trends and Insights. https://www.mandiant.com/resources/m-trends
Cobalt Strike. (2022). Cobalt Strike Documentation. https://www.cobaltstrike.com/help-beacon
Skordas, I. (2016). DNSCat2: DNS Communication Tool. GitHub. https://github.com/iagox86/dnscat2
Farmer, D., & Venema, W. (1993). Improving the Security of Your Site by Breaking Into It. https://www.porcupine.org/forensics/forensic-discovery/chapter2.pdf
Cisco Talos. (2015). Janicab: Mac OS X Malware Using YouTube as C2. https://blog.talosintelligence.com/2015/07/janicab-mac-os-x-malware-uses-youtube.html
Bishop Fox. (2022). Sliver C2 Framework. https://github.com/BishopFox/sliver
Sommer, R., & Paxson, V. (2010). Outside the Closed World: On Using Machine Learning for Network Intrusion Detection. IEEE Symposium on Security and Privacy. https://doi.org/10.1109/SP.2010.25 DOI: https://doi.org/10.1109/SP.2010.25
Lee, S., & Lee, H. (2013). Cyber Threat Detection based on Machine Learning. International Journal of Computer Applications, 76(22), 1-5.
Antonakakis, M. et al. (2012). Detecting Malware Domains at the Upper DNS Hierarchy. USENIX Security Symposium. https://www.usenix.org/system/files/conference/usenixsecurity12/sec12-final39.pdf
Dagon, D., Gu, G., Lee, C., & Lee, W. (2007). A Taxonomy of Botnet Structures. In Computer Security Applications Conference. https://doi.org/10.1109/ACSAC.2007.44 DOI: https://doi.org/10.1109/ACSAC.2007.4413000
MISP Project. (2022). MISP: Open Source Threat Intelligence Platform. https://www.misp-project.org
MITRE ATT&CK. (2024). Command and Control Techniques. https://attack.mitre.org/tactics/TA0011/
CrowdStrike. (2023). How EDR Works to Stop Attacks. https://www.crowdstrike.com/cybersecurity-101/endpoint-security/what-is-edr/
Roesch, M. (1999). Snort – Lightweight Intrusion Detection for Networks. In LISA. https://doi.org/10.5555/1039834.1039864
Zeek Project. (2022). Zeek Documentation. https://docs.zeek.org/en/current/
Suricata IDS. (2022). Suricata User Guide. https://suricata-ids.org/docs/
Splunk. (2023). Security Information and Event Management. https://www.splunk.com/en_us/solutions/solution-areas/security.html
NIST. (2020). Zero Trust Architecture. NIST Special Publication 800-207. https://doi.org/10.6028/NIST.SP.800-207 DOI: https://doi.org/10.6028/NIST.SP.800-207
Cisco. (2018). Network Segmentation Design Guide. https://www.cisco.com/c/en/us/solutions/collateral/enterprise/design-zone-smart-business-architecture/sba-wan-cloud-qoe-design-guide.html
Palo Alto Networks. (2021). Blocking Command and Control Traffic. https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000PLMdCAO
MISP Project. (2022). MISP: Open Source Threat Intelligence Platform. https://www.misp-project.org
Cisco Umbrella. (2021). DNS-Layer Security. https://umbrella.cisco.com/products/dns-layer-security
Pi-hole. (2022). Pi-hole Documentation. https://docs.pi-hole.net
Proofpoint. (2020). Email Fraud and Phishing Trends. https://www.proofpoint.com/us/resources/threat-reports/email-fraud-phishing
KnowBe4. (2021). Phishing Benchmarking Report. https://www.knowbe4.com/phishing-benchmarking-report
Kindervag, J. (2010). No More Chewy Centers: Introducing the Zero Trust Model of Information Security. Forrester Research.
Microsoft. (2021). Zero Trust Deployment Guide. https://docs.microsoft.com/en-us/security/zero-trust/
NIST. (2012). Computer Security Incident Handling Guide. NIST Special Publication 800-61 Revision 2. https://doi.org/10.6028/NIST.SP.800-61r2
SANS Institute. (2018). Incident Handler's Handbook. https://www.sans.org/white-papers/incident-handlers-handbook/
Mandia, K., Prosise, C., & Pepe, M. (2014). Incident Response & Computer Forensics (3rd ed.). McGraw-Hill Education.
MITRE ATT&CK. (2024). Mitigation Strategies for Command and Control. https://attack.mitre.org/mitigations/enterprise/
US-CERT. (2019). Technical Approaches to Uncovering and Remediating Malicious Activity. https://us-cert.cisa.gov/ncas/alerts/TA18-074A
FireEye Mandiant. (2020). Incident Response Playbook: Command and Control. https://www.fireeye.com/services.html
MITRE. (2020). Adversary Emulation Plans. https://attack.mitre.org/resources/adversary-emulation-plans/
SANS Institute. (2019). Purple Team Tactics: Bridging the Gap Between Red and Blue. https://www.sans.org/white-papers/purple-team-tactics/
Cobalt Strike. (2022). Cobalt Strike Documentation. https://www.cobaltstrike.com/help-beacon
Bishop Fox. (2022). Sliver C2 Framework. https://github.com/BishopFox/sliver
Mythic Project. (2023). Mythic Documentation. https://docs.mythic-c2.net/
Zeek Project. (2022). Zeek Documentation. https://docs.zeek.org/en/current/
Cisco. (2021). Detecting DNS Tunneling and Covert Channels. https://www.cisco.com/c/en/us/about/security-center/dns-tunneling.html
CrowdStrike. (2023). How EDR Works to Stop Attacks. https://www.crowdstrike.com/cybersecurity-101/endpoint-security/what-is-edr/
Microsoft. (2021). Red and Blue Team Collaboration for Cybersecurity. https://docs.microsoft.com/en-us/security/red-team-blue-team
FireEye Mandiant. (2020). Command and Control Fundamentals. https://www.fireeye.com
MITRE ATT&CK. (2024). Command and Control Techniques. https://attack.mitre.org/tactics/TA0011/
NIST. (2012). Computer Security Incident Handling Guide. NIST Special Publication 800-61 Revision 2. https://doi.org/10.6028/NIST.SP.800-61r2 DOI: https://doi.org/10.6028/NIST.SP.800-61r2
SANS Institute. (2018). Incident Handler's Handbook.
Downloads
Published
Issue
Section
License
Copyright (c) 2025 International Journal of Scientific Research in Computer Science, Engineering and Information Technology

This work is licensed under a Creative Commons Attribution 4.0 International License.