- Home
- Techniques
- Enterprise
- Application Layer Protocol
Application Layer Protocol
Sub-techniques (4)
Adversaries may communicate using application layer protocols to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
Adversaries may utilize many different protocols, including those used for web browsing, transferring files, electronic mail, or DNS. For connections that occur internally within an enclave (such as those between a proxy or pivot node and other nodes), commonly used protocols are SMB, SSH, or RDP.
Procedure Examples
| Name | Description |
|---|---|
| Cobalt Strike |
Cobalt Strike conducts peer-to-peer communication over Windows named pipes encapsulated in the SMB protocol. All protocols use their standard assigned ports.[1] |
| Dragonfly 2.0 |
Dragonfly 2.0 used SMB for C2.[4] |
| Duqu |
Duqu uses a custom command and control protocol that communicates over commonly used ports, and is frequently encapsulated by application layer protocols.[2] |
| Magic Hound |
Magic Hound malware has used IRC for C2.[5] |
| NETEAGLE |
Adversaries can also use NETEAGLE to establish an RDP connection with a controller over TCP/7519. |
| Regin |
The Regin malware platform supports many standard protocols, including SMB.[3] |
| Rocke |
Rocke issued wget requests from infected systems to the C2.[6] |
Mitigations
| Mitigation | Description |
|---|---|
| Network Intrusion Prevention |
Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level. |
Detection
Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect application layer protocols that do not follow the expected protocol standards regarding syntax, structure, or any other variable adversaries could leverage to conceal data.[7]
References
- Strategic Cyber LLC. (2017, March 14). Cobalt Strike Manual. Retrieved May 24, 2017.
- Symantec Security Response. (2011, November). W32.Duqu: The precursor to the next Stuxnet. Retrieved September 17, 2015.
- Kaspersky Lab's Global Research and Analysis Team. (2014, November 24). THE REGIN PLATFORM NATION-STATE OWNAGE OF GSM NETWORKS. Retrieved December 1, 2014.
- US-CERT. (2018, March 16). Alert (TA18-074A): Russian Government Cyber Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved June 6, 2018.
- Lee, B. and Falcone, R. (2017, February 15). Magic Hound Campaign Attacks Saudi Targets. Retrieved December 27, 2017.
- Liebenberg, D.. (2018, August 30). Rocke: The Champion of Monero Miners. Retrieved May 26, 2020.
- Gardiner, J., Cova, M., Nagaraja, S. (2014, February). Command & Control Understanding, Denying and Detecting. Retrieved April 20, 2016.