PRESS RELEASE

CUPERTINO, CA " March 2, 2010 " ArcSight, Inc. (NASDAQ: ARST), a leading global provider of security and compliance management solutions that protect enterprises and government agencies, today announced the latest version of ArcSight Express, a family of appliances that integrate security event correlation, log management, IT search, and NetFlow monitoring into a single, easy to deploy solution.

ArcSight Express is in use today at organizations around the globe, protecting networks from external threats, from compliance risks, and from internal theft of sensitive information. The latest version of ArcSight Express adds rules-based guided response capabilities, to dramatically cut the time between detection and remediation of threats.

"We believe today's security threats are increasing in sophistication, frequency, and impact," said Tom Reilly, president and CEO of ArcSight. "Organizations are losing bank funds to bot fraud, losing confidential data to breaches, and losing network control to hackers and worms. ArcSight Express gives midsize and large organizations a cost effective and easy to use way to address these threats."

"ArcSight Express is very intuitive and easy to use. It is a perfect fit for the size and scope of our business and has allowed us to expand into new markets," said Chris Van Houtte, Vice President of Information Technology at IWCO Direct. "We needed a solution that would not demand significant resources and that could provide immediate benefit. We were instantly impressed with the ease of use of ArcSight Express. The rules and reports were already set up and easy to customize, so we were able to achieve many of our goals right out of the gate. It is a perfect fit for the size and scope of our business."

ArcSight Express provides several important functions and benefits for organizations worried about securing their operations in the face of a growing threat landscape but with shrinking resources and budgets:

* Universal Data Collection " By collecting log data, including syslog data, NetFlow, transaction, application, identity, legacy, and other information, ArcSight Express protects against sophisticated threats that would otherwise slip through network defenses. The benefit is visibility across the corporate network, with less effort.

* Cost Effective Storage " By automatically managing long term log data, for up to multiple years, ArcSight Express provides easy compliance reporting. The benefit is easier audits with less time and cost.

* World-Class Correlation " By applying advanced commercial real-time correlation techniques, ArcSight Express can detect even very subtle attacks. The benefit is better security with fewer resources.

* Regulation-Specific Applications " By supporting pre-built applications for SOX, PCI DSS, HIPAA, and other regulations, ArcSight Express delivers audit-reporting best practices out of the box. The benefit is faster time to compliance.

* Rules-Based Guided Response " By delivering automatic threat response, ArcSight Express cuts the time between detection of threats and elimination of those threats. The benefit is a lower risk of data loss, with less time and effort.

ArcSight Express is available in multiple configurations, effective immediately. With pre-configured services offerings, ArcSight Express can be deployed within days. Pricing starts at $45,000.

About ArcSight

ArcSight (NASDAQ: ARST) is a leading global provider of security and compliance management solutions that protect businesses and government agencies. ArcSight identifies, assesses, and mitigates both internal and external cyber threats and risks across the organization for activities associated with critical assets and processes. With the market-leading ArcSight SIEM platform, organizations can proactively safeguard their assets, comply with corporate and regulatory policy and control the risks associated with cyber-theft, cyber-fraud, cyber-warfare and cyber-espionage. For more information, visit www.arcsight.com. (ARST-IR)