Hidden and Uncontrolled - On the Emergence of Network Steganographic Threats

Network steganography is the art of hiding secret information within innocent network transmissions. Recent findings indicate that novel malware is increasingly using network steganography. Similarly, other malicious activities can profit from network steganography, such as data leakage or the exchange of pedophile data. This paper provides an introduction to network steganography and highlights its potential application for harmful purposes. We discuss the issues related to countering network steganography in practice and provide an outlook on further research directions and problems.Comment: 11 page

Employing Entropy in the Detection and Monitoring of Network Covert Channels

The detection of covert channels has quickly become a vital need due to their pervasive nature and the increasing popularity of the Internet. In recent years, new and innovative methods have been proposed to aid in the detection of covert channels. Existing detection schemes are often too specific and are ineffective against new covert channels. In this paper, we expound upon previous work done with timing channels and apply it to detecting covert storage channels. Our approach is based on the assumption that the entropy of covert channels will vary from that of previously observed, legitimate, communications. This change in the entropy of a process provides us with a method for identifying storage channels. Using this assumption we created proof of concept code capable of detecting various covert storage channels. The results of our experiments demonstrate that we can successfully detect existing and unpublished covert storage channels accurately

Network-aware Active Wardens in IPv6

Every day the world grows more and more dependent on digital communication. Technologies like e-mail or the World Wide Web that not so long ago were considered experimental, have first become accepted and then indispensable tools of everyday life. New communication technologies built on top of the existing ones continuously race to provide newer and better functionality. Even established communication media like books, radio, or television have become digital in an effort to avoid extinction. In this torrent of digital communication a constant struggle takes place. On one hand, people, organizations, companies and countries attempt to control the ongoing communications and subject them to their policies and laws. On the other hand, there oftentimes is a need to ensure and protect the anonymity and privacy of the very same communications. Neither side in this struggle is necessarily noble or malicious. We can easily imagine that in presence of oppressive censorship two parties might have a legitimate reason to communicate covertly. And at the same time, the use of digital communications for business, military, and also criminal purposes gives equally compelling reasons for monitoring them thoroughly. Covert channels are communication mechanisms that were never intended nor designed to carry information. As such, they are often able to act ``below\u27\u27 the notice of mechanisms designed to enforce security policies. Therefore, using covert channels it might be possible to establish a covert communication that escapes notice of the enforcement mechanism in place. Any covert channel present in digital communications offers a possibility of achieving a secret, and therefore unmonitored, communication. There have been numerous studies investigating possibilities of hiding information in digital images, audio streams, videos, etc. We turn our attention to the covert channels that exist in the digital networks themselves, that is in the digital communication protocols. Currently, one of the most ubiquitous protocols in deployment is the Internet Protocol version 4 (IPv4). Its universal presence and range make it an ideal candidate for covert channel investigation. However, IPv4 is approaching the end of its dominance as its address space nears exhaustion. This imminent exhaustion of IPv4 address space will soon force a mass migration towards Internet Protocol version 6 (IPv6) expressly designed as its successor. While the protocol itself is already over a decade old, its adoption is still in its infancy. The low acceptance of IPv6 results in an insufficient understanding of its security properties. We investigated the protocols forming the foundation of the next generation Internet, Internet Protocol version 6 (IPv6) and Internet Control Message Protocol (ICMPv6) and found numerous covert channels. In order to properly assess their capabilities and performance, we built cctool, a comprehensive covert channel tool. Finally, we considered countermeasures capable of defeating discovered covert channels. For this purpose we extended the previously existing notions of active wardens to equip them with the knowledge of the surrounding network and allow them to more effectively fulfill their role

A Deep Learning Based Approach To Detect Covert Channels Attacks and Anomaly In New Generation Internet Protocol IPv6

The increased dependence of internet-based technologies in all facets of life challenges the government and policymakers with the need for effective shield mechanism against passive and active violations. Following up with the Qatar national vision 2030 activities and its goals for “Achieving Security, stability and maintaining public safety” objectives, the present paper aims to propose a model for safeguarding the information and monitor internet communications effectively. The current study utilizes a deep learning based approach for detecting malicious communications in the network traffic. Considering the efficiency of deep learning in data analysis and classification, a convolutional neural network model was proposed. The suggested model is equipped for detecting attacks in IPv6. The performance of the proposed detection algorithm was validated using a number of datasets, including a newly created dataset. The performance of the model was evaluated for covert channel, DDoS attacks detection in IPv6 and for anomaly detection. The performance assessment produced an accuracy of 100%, 85% and 98% for covert channel detection, DDoS detection and anomaly detection respectively. The project put forward a novel approach for detecting suspicious communications in the network traffic

ICMP Covert Channel Resiliency

The ICMP protocol has been widely used and accepted as a covert channel. While the ICMP protocol is very simple to use, modern security approaches such as firewalls, deep-packet inspection and intrusion detection systems threaten the use of ICMP for a reliable means for a covert channel. This study explores the modern usefulness of ICMP with typical security measures in place. Existing ICMP covert channel solutions are examined for compliance with standard RFCs and resiliency with modern security approaches

Detecting Selected Network Covert Channels Using Machine Learning

International audienceNetwork covert channels break a computer's security policy to establish a stealthy communication. They are a threat being increasingly used by malicious software. Most previous studies on detecting network covert channels using Machine Learning (ML) were tested with a dataset that was created using one single covert channel tool and also are ineffective at classifying covert channels into patterns. In this paper, selected ML methods are applied to detect popular network covert channels. The capacity of detecting and classifying covert channels with high precision is demonstrated. A dataset was created from nine standard covert channel tools and the covert channels are then accordingly classified into patterns and labelled. Half of the generated dataset is used to train three different ML algorithms. The remaining half is used to verify the algorithms' performance. The tested ML algorithms are Support Vector Machines (SVM), k-Nearest Neighbors (k-NN) and Deep Neural Networks (DNN). The k-NN model demonstrated the highest precision rate at 98% detection of a given covert channel and with a low false positive rate of 1%

Covert Channels in SIP for VoIP signalling

In this paper, we evaluate available steganographic techniques for SIP (Session Initiation Protocol) that can be used for creating covert channels during signaling phase of VoIP (Voice over IP) call. Apart from characterizing existing steganographic methods we provide new insights by introducing new techniques. We also estimate amount of data that can be transferred in signalling messages for typical IP telephony call.Comment: 8 pages, 4 figure

PadSteg: Introducing Inter-Protocol Steganography

Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents inter-protocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.Comment: 9 pages, 12 figures, 5 table