Containment of fast scanning computer network worms

This paper presents a mechanism for detecting and containing fast scanning computer network worms. The countermeasure mechanism, termed NEDAC, uses a behavioural detection technique that observes the absence of DNS resolution in newly initiated outgoing connections. Upon detection of abnormal behaviour by a host, based on the absence of DNS resolution, the detection system then invokes a data link containment system to block traffic from the host. The concept has been demonstrated using a developed prototype and tested in a virtualised network environment. An empirical analysis of network worm propagation has been conducted based on the characteristics of reported contemporary vulnerabilities to test the capabilities of the countermeasure mechanism. The results show that the developed mechanism is sensitive in detecting and blocking fast scanning worm infection at an early stage

Software Defined Networking Opportunities for Intelligent Security Enhancement of Industrial Control Systems

In the last years, cyber security of Industrial Control Systems (ICSs) has become an important issue due to the discovery of sophisticated malware that by attacking Critical Infrastructures, could cause catastrophic safety results. Researches have been developing countermeasures to enhance cyber security for pre-Internet era systems, which are extremely vulnerable to threats. This paper presents the potential opportunities that Software Defined Networking (SDN) provides for the security enhancement of Industrial Control Networks. SDN permits a high level of configuration of a network by the separation of control and data planes. In this work, we describe the affinities between SDN and ICSs and we discuss about implementation strategies

Disguised Executable Files in Spear-Phishing Emails: Detecting the Point of Entry in Advanced Persistent Threat

In recent years, cyber attacks have caused substantial financial losses and been able to stop fundamental public services. Among the serious attacks, Advanced Persistent Threat (APT) has emerged as a big challenge to the cyber security hitting selected companies and organisations. The main objectives of APT are data exfiltration and intelligence appropriation. As part of the APT life cycle, an attacker creates a Point of Entry (PoE) to the target network. This is usually achieved by installing malware on the targeted machine to leave a back-door open for future access. A common technique employed to breach into the network, which involves the use of social engineering, is the spear phishing email. These phishing emails may contain disguised executable fi les. This paper presents the disguised executable le detection (DeFD) module, which aims at detecting disguised exe files transferred over the network connections. The detection is based on a comparison between the MIME type of the transferred fi le and the fi le name extension. This module was experimentally evaluated and the results show a successful detection of disguised executable files

Malware propagation in smart grid monocultures

Intelligente Stromnetze benötigen Kommunikationstechnologien, um Sensordaten und Kontrollinformationen zu übertragen. Der modulare Aufbau von Hardware, Firmware und Software sowie deren teilweise Wiederverwendung in verschiedenen Komponenten des Smart Grids ermöglichen eine Senkung der Herstellungs- und Investitionskosten. Je geringer die Anzahl ausgerollter Hardware-, Firmware- und Softwareversionen im Feld ist, desto geringer sind die zu erwartenden Betriebskosten wie etwa für automatisierte Updates, Gerätewartung, Geräteersatz und Schulung. Diese finanziellen Anreize haben eine äußerst homogene Gerätebasis im Smart Grid zur Folge. Das führt zu optimalen Bedingungen für die Ausbreitung von Malware in Smart Grid-Kommunikationsnetzen.Smart power grids require a communication infrastructure to collect sensor data and to send control commands. The common trend for cost reduction influences the architecture, implementation, networking, and operation of smart grid devices. Whereas hardware and software reuse are imperative for vendors to lower device costs, utility companies substantially decrease their operational costs by deploying a homogeneous device base. Thousands of smart meters that feature identical hardware, firmware, and software, are one main prerequisite for automated maintenance, support, and device replacement. However, these cost savings create optimum conditions for malware propagation and infection in the grids’ control networks.In this paper we show how monocultures in device types can lead to critical situations if malware exploits a common vulnerability. Although we assume that classical defensive measures, e.g., firewalls, virtual networks, and intrusion detection, are in place, we argue that new or unpatched vulnerabilities cannot be ruled out and may lead to a very fast distribution of malware in large parts of the smart grids’ control network. Besides showing how fast malware can spread in device monocultures, we also discuss effective defensive measures that can support utility companies in preventing or containing malware distribution