5 reasons why SIEM is more important than ever

This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note that it will likely favor the submitter's approach. 

IT environments are growing ever more distributed, complex and difficult to manage, making the role of security information and event management (SIEM) technology more important than ever. Here's why.
* Compliance: Almost every business is bound by some sort of regulation, such as PCI-DSS, HIPAA and Sarbanes-Oxley (SOX). Attaining and maintaining compliance with these regulations is a daunting task. SIEM technologies can address compliance requirements both directly and indirectly.

Virtually every regulatory mandate requires some form of log management to maintain an audit trail of activity. SIEMs provide a mechanism to rapidly and easily deploy a log collection infrastructure that directly supports this requirement, and allows both instant access to recent log data, as well as archival and retrieval of older log data. Alerting and correlation capabilities also satisfy routine log data review requirements, an otherwise tedious and daunting task when done manually.
In addition, SIEM reporting capabilities provide audit support to verify that certain requirements are being met. Most SIEM vendors supply packaged reports that directly map to specific compliance regulations. These can be run with minimal configuration, and will aggregate and generate reports from across the enterprise to meet audit requirements.
* Operations support: The size and complexity of today's enterprises is growing exponentially, along with the number of IT personnel to support them. Operations are often split among different groups such as the Network Operations Center (NOC), the Security Operations Center (SOC), the server team, desktop team, etc., each with their own tools to monitor and respond to events. This makes information sharing and collaboration difficult when problems occur. A SIEM can pull data from disparate systems into a single pane of glass, allowing for efficient cross-team collaboration in extremely large enterprises.
* Zero-day threat detection: New attack vectors and vulnerabilities are discovered every day. Firewalls, IDS/IPS and AV solutions all look for malicious activity at various points within the IT infrastructure, from the perimeter to endpoints. However, many of these solutions are not equipped to detect zero-day attacks. A SIEM can detect activity associated with an attack rather than the attack itself. For instance, a well-crafted spear-phishing attack using a zero-day exploit has a high likelihood of making it through spam filters, firewalls and antivirus software, and being opened by a target user.
A SIEM can be configured to detect activity surrounding such an attack. For example, a PDF exploit generally causes the Adobe Reader process to crash. Shortly thereafter, a new process will launch that either listens for an incoming network connection or initiates an outbound connection to the attacker. Many SIEMs offer enhanced endpoint monitoring capabilities that keep track of processes starting and stopping and network connections opening and closing. By correlating process activity and network connections from host machines a SIEM can detect attacks, without ever having to inspect packets or payloads. While IDS/IPS and AV do what they do well, a SIEM provides a safety net that can catch malicious activities that slip through traditional defenses.
* Advanced persistent threats: APTs have been in the news a lot, with many experts claiming they were responsible for the high-profile breaches at RSA, Lockheed Martin and others. An APT is generally defined as a sophisticated attack that targets a specific piece of data or infrastructure, using a combination of attack vectors and methods, simple or advanced, to elude detection. In response, many organizations have implemented a defense in depth strategy around their critical assets using firewalls and IDS/IPS at the perimeter, two-factor authentication, internal firewalls, network segmentation, HIDS, AV, etc.
All of these devices generate a huge amount of data, which is difficult to monitor. A security team cannot realistically have eight dashboards open and correlate events among several components fast enough to keep up with the packets traversing the network. SIEM technologies bring all of these controls together into a single engine, capable of continuous real-time monitoring and correlation across the breadth and depth of the enterprise.
But what if an attack is not detected by the SIEM? After a host is compromised, the attacker must still locate the target data and extract it. Some SIEM correlation engines are able to monitor for a threshold of unique values. For example, a rule that looks for a certain number of unsuccessful access attempts on port 445 (or ports 137, 138 and 139 if NetBIOS is used) from the same host within a short time frame would identify a scan for shared folders. A similar rule looking for standard database ports would indicate a scan for databases listening on the network.
Through the integration of whitelisting with SIEM, it becomes trivial to identify which hosts and accounts are attempting to access data that they shouldn't be accessing. Meanwhile, implementing File Integrity Monitoring with a SIEM can correlate data being accessed with outbound network traffic from the same host to detect data leakage. If a FIM event shows that the critical data was accessed along with a thumb drive being plugged into the same host that was accessing the critical data, an alarm can be generated to notify security personnel of a potential breach.
* Forensics: A forensics investigation can be a long, drawn-out process. Not only must a forensics analyst interpret log data to determine what actually happened, the analyst must preserve the data in a way that makes it admissible in a court of law. By storing and protecting historical logs, and providing tools to quickly navigate and correlate the data, SIEM technologies allow for rapid, thorough and court-admissible forensics investigations.
Since log data represents the digital fingerprints of all activity that occurs across IT infrastructures, it can be mined to detect security, operations and regulatory compliance problems. Consequently, SIEM technology, with its ability to automate log monitoring, correlation, pattern recognition, alerting and forensic investigations, is emerging as a central nervous system for gathering and generating IT intelligence.