Publication detail

Learning Probabilistic Automata in the Context of IEC 104

HAVLENA, V. HOLÍK, L. MATOUŠEK, P.

Original Title

Learning Probabilistic Automata in the Context of IEC 104

Type

report

Language

English

Original Abstract

Industrial Control System (ICS) communication transmits monitoring and control data between industrial processes and the control station. ICS systems cover various domains of critical infrastructure such as the power plants, water and gas distribution, or aerospace traffic control. Security of ICS systems is usually implemented on the perimeter of the network using ICS enabled firewalls or Intrusion Detection Systems (IDSs). These techniques are helpful against external attacks, however, they are not able to eff ectively detect internal threats originating from a compromised device with malicious software. In order to mitigate or eliminate internal threats against the ICS system, we need to monitor ICS traffic and detect suspicious data transmissions that differ from common operational  communication. In our research, we obtain ICS monitoring data using standardized IPFIX flows extended with meta data extracted from ICS protocol headers. Unlike other anomaly detection approaches, we focus on modelling the semantics of ICS communication obtained from the IPFIX  flows that describes typical conversational patterns. This report presents a technique for modelling ICS conversations using frequency prefi x trees (PT) and Deterministic Probabilistic Automata (DPA). As demonstrated on the attack scenarios, these models are efficient to detect common cyber attacks like the command injection, packet manipulation, network scanning, or lost connection. An important advantage of our approach is that the proposed technique can be easily integrated into common security information and event management (SIEM) systems with Netflow/IPFIX support. Our experiments are performed on IEC 60870-5-104 (aka IEC 104) control communication that is widely used for the substation control in smart grids.

Keywords

probabilistic automata, IEC 104, Alergia

Authors

HAVLENA, V.; HOLÍK, L.; MATOUŠEK, P.

Released

1. 12. 2020

Publisher

Faculty of Information Technology BUT

Location

IT-TR-2020-01, Brno

Pages count

26

URL

https://www.fit.vut.cz/research/publication/12355/

BibTex

@techreport{BUT168673,
  author="Vojtěch {Havlena} and Lukáš {Holík} and Petr {Matoušek}",
  title="Learning Probabilistic Automata in the Context of IEC 104",
  year="2020",
  publisher="Faculty of Information Technology BUT",
  address="IT-TR-2020-01, Brno",
  pages="26",
  url="https://www.fit.vut.cz/research/publication/12355/"
}