It is well known that Anti-Virus technology is fallible and will continue to be so by design. The landscape (Threatscape?) is always changing and AV systems will typically update their malware signature repositories at least once per day in an attempt to keep up with the new threats that have been isolated since the previous update. Show
So how secure does your organization need to be? 80%? 90%? Because if you rely on traditional anti-virus defenses this is the best you can hope to achieve unless you implement additional defense layers such as FIM (file integrity monitoring) and SIEM (event log analysis). Anti-Virus Technology - Complete with Malware Blind SpotsAny Anti-Virus software has an inherent weakness in that it relies on a library of malware ‘signatures’ to identify the viruses, Trojans, and worms it is seeking to remove. This repository of malware signatures is regularly updated, sometimes several times a day depending on the developer of the software being used. The problem is that the AV developer usually needs to have direct experience of any new strains of malware in order to counteract them. The concept of a 'zero-day' threat is one that uses a new variant of malware yet to be identified by the AV system. By definition, AV systems are blind to ‘zero-day’ threats, even to the point whereby new versions of an existing malware strain may be able to evade detection. Modern malware often incorporates the means to mutate, allowing it to change its makeup every time it is propagated and so improve its effectiveness at evading the AV system. Similarly other automated security technologies, such as the sandbox or quarantine approach, that aim to block or remove malware all suffer from the same blind spots. If the malware is new though – a zero-day threat – then by definition there is no signature because it has not been identified before. The unfortunate reality is that the unseen cyber-enemy also knows that new is best if they want their malware to evade detection. This is evident by the fact that in excess of 10 million new malware samples will be identified in any 6 month period. In other words, most organizations typically have very effective defenses against known enemies – any malware that has been previously identified will be stopped dead in its tracks by the IPS, anti-virus system, or any other web/mail filtering with sandbox technology. However, it is also true that the majority of these same organizations have little or no protection against the zero-day threat. File Integrity Monitoring - The 2nd Line Anti-Virus Defense System for when your Anti-Virus System FailsFile Integrity Monitoring serves to record any changes to the file system i.e. core operating system files or program components. In this way, any malware entering your key server platforms will be detected, no matter how subtle or stealthy the attack. In addition, FIM Technology will also ensure other vulnerabilities are screened out from your systems by ensuring best practices in securely configuring your Operating Systems have been applied. For example, any configuration settings such as user accounts, password policy, running services and processes, installed software, management and monitoring functions are all potential vectors for security breaches. In the Windows environment, the Windows Local Security Policy has been gradually extended over time to include greater restrictions on numerous functions that have been exploited in the past but this in itself is a highly complex area to configure correctly. To then maintain systems in this secure configured state is impossible without automated file integrity monitoring technology. Likewise, SIEM or Security Information and Event Log Management systems are designed to gather and analyze all system audit trails/event logs and correlate these with other security information to present a true picture of whether anything unusual and potentially security-threatening is happening. It is telling that widely adopted and practiced security standards such as the PCI DSS place these elements at their core as a means of maintaining system security and verifying that key processes like Change Management are being observed. SummaryAnti-virus technology is an essential and highly valuable line of defense for any organization. However, it is vital that the limitations and therefore vulnerabilities of this technology are understood and additional layers of security implemented to compensate. File Integrity Monitoring and Event Log Analysis are the ideal counterparts to an Anti-Virus system in order to provide complete security against the modern malware threat. What is an intrusion detection system (IDS)?An intrusion detection system (IDS) is a system that monitors network traffic for suspicious activity and alerts when such activity is discovered. While anomaly detection and reporting are the primary functions of an IDS, some intrusion detection systems are capable of taking actions when malicious activity or anomalous traffic is detected, including blocking traffic sent from suspicious Internet Protocol (IP) addresses. An IDS can be contrasted with an intrusion prevention system (IPS), which monitors network packets for potentially damaging network traffic, like an IDS, but has the primary goal of preventing threats once detected, as opposed to primarily detecting and recording threats. How do intrusion detection systems work?Intrusion detection systems are used to detect anomalies with the aim of catching hackers before they do real damage to a network. IDSes can be either network- or host-based. A host-based intrusion detection system is installed on the client computer, while a network-based intrusion detection system resides on the network. Intrusion detection systems work by either looking for signatures of known attacks or deviations from normal activity. These deviations or anomalies are pushed up the stack and examined at the protocol and application layer. They can effectively detect events such as Christmas tree scans and Domain Name System (DNS) poisonings. An IDS may be implemented as a software application running on customer hardware or as a network security appliance. Cloud-based intrusion detection systems are also available to protect data and systems in cloud deployments. Different types of intrusion detection systemsIDSes come in different flavors and detect suspicious activities using different methods, including the following:
Historically, intrusion detection systems were categorized as passive or active. A passive IDS that detected malicious activity would generate alert or log entries but would not take action. An active IDS, sometimes called an intrusion detection and prevention system (IDPS), would generate alerts and log entries but could also be configured to take actions, like blocking IP addresses or shutting down access to restricted resources. Snort -- one of the most widely used intrusion detection systems -- is an open source, freely available and lightweight NIDS that is used to detect emerging threats. Snort can be compiled on most Unix or Linux operating systems (OSes), with a version available for Windows as well. Capabilities of intrusion detection systemsIntrusion detection systems monitor network traffic in order to detect when an attack is being carried out by unauthorized entities. IDSes do this by providing some -- or all -- of the following functions to security professionals:
Benefits of intrusion detection systemsIntrusion detection systems offer organizations several benefits, starting with the ability to identify security incidents. An IDS can be used to help analyze the quantity and types of attacks. Organizations can use this information to change their security systems or implement more effective controls. An intrusion detection system can also help companies identify bugs or problems with their network device configurations. These metrics can then be used to assess future risks. Intrusion detection systems can also help enterprises attain regulatory compliance. An IDS gives companies greater visibility across their networks, making it easier to meet security regulations. Additionally, businesses can use their IDS logs as part of the documentation to show they are meeting certain compliance requirements. Intrusion detection systems can also improve security responses. Since IDS sensors can detect network hosts and devices, they can also be used to inspect data within the network packets, as well as identify the OSes of services being used. Using an IDS to collect this information can be much more efficient than manual censuses of connected systems. Challenges of intrusion detection systemsIDSes are prone to false alarms -- or false positives. Consequently, organizations need to fine-tune their IDS products when they first install them. This includes properly configuring their intrusion detection systems to recognize what normal traffic on their network looks like compared to potentially malicious activity. However, despite the inefficiencies they cause, false positives don't usually cause serious damage to the actual network and simply lead to configuration improvements. A much more serious IDS mistake is a false negative, which is when the IDS misses a threat and mistakes it for legitimate traffic. In a false negative scenario, IT teams have no indication that an attack is taking place and often don't discover until after the network has been affected in some way. It is better for an IDS to be oversensitive to abnormal behaviors and generate false positives than it is to be undersensitive, generating false negatives. False negatives are becoming a bigger issue for IDSes -- especially SIDSes -- since malware is evolving and becoming more sophisticated. It's hard to detect a suspected intrusion because new malware may not display the previously detected patterns of suspicious behavior that IDSes are typically designed to detect. As a result, there is an increasing need for IDSes to detect new behavior and proactively identify novel threats and their evasion techniques as soon as possible. IDS versus IPSAn IPS is similar to an intrusion detection system but differs in that an IPS can be configured to block potential threats. Like intrusion detection systems, IPSes can be used to monitor, log and report activities, but they can also be configured to stop threats without the involvement of a system administrator. An IDS simply warns of suspicious activity taking place, but it doesn't prevent it. An IPS is typically located between a company's firewall and the rest of its network and may have the ability to stop any suspected traffic from getting to the rest of the network. Intrusion prevention systems execute responses to active attacks in real time and can actively catch intruders that firewalls or antivirus software may miss.  However, organizations should be careful with IPSes because they can also be prone to false positives. An IPS false positive is likely to be more serious than an IDS false positive because the IPS prevents the legitimate traffic from getting through, whereas the IDS simply flags it as potentially malicious. It has become a necessity for most organizations to have either an IDS or an IPS -- and usually both -- as part of their security information and event management (SIEM) framework. Several vendors integrate an IDS and an IPS together in one product -- known as unified threat management (UTM) -- enabling organizations to implement both simultaneously alongside firewalls and systems in their security infrastructure. What is the difference between a sensor and a collector?What is the difference between a sensor and a collector, in the context of SIEM? A SIEM collector parses input (such as log files or packet traces) into a standard format that can be recorded within the SIEM and interpreted for event correlation. A sensor collects data from the network media.
What is the principal use of grep in relation to log files?One of the simplest ways to analyze logs is by performing plain text searches using grep. grep is a command line tool that can search for matching text in a file, or in output from other commands.
What are the primary features of a security information event management SIEM tool quizlet?real time reporting, log collection, normalization, correlation, and aggregation.
What distinguishes host based firewalls from a network appliance?While Network Based Firewall filters traffic going from Internet to secured LAN and vice versa, a host based firewall is a software application or suite of applications installed on a single computer and provides protection to the host.
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If a windows system file fails a file integrity check, should you suspect a malware infection?
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