ArcSight, Inc. (NASDAQ: ARST), a leading global provider of security and compliance management solutions that protect enterprises and government agencies, today announced that according to a recent report from TheInfoPro, more Fortune 1000 (F1000) companies are indicating using ArcSight for event log management and security information event management (SIEM) than any other vendor. TheInfoPro™ Information Security Study: Technology Roadmap (Q4 2009) ranks ArcSight as the top "in use" vendor for both event log management system and SIEM product categories among F1000 security professionals.

The study also ranks event log management systems number one and SIEM number six on the Information Security Technology Heat Index® for F1000, which gauges the immediacy of user needs and planned spending on technology.

"ArcSight is proud to have its enterprise threat and risk solutions acknowledged by TheInfoPro's Information Security Study and their interviewees yet again," said Tom Reilly, president and CEO of ArcSight. "We believe that, as cyber criminal attacks increase in scope and grow in sophistication, organizations are using event log management and SIEM to not only investigate attacks, but identify threats before they create problems."

TheInfoPro's Information Security Study: Technology Roadmap (Q4 2009) is based on interviews with 259 information security professionals at large and midsize enterprises in North America and Europe that were completed in December 2009. It provides detailed plans about usage patterns for 38 information security technologies that fall under the following categories: network access, network malware protection, network communication content protection, identity management, vulnerability management, access management, data protection and outsourced security services. For each technology, IT pros were asked about the status of implementation and about the vendors they are using or considering. In addition, data is collected on the current and projected spending on the technology. Finally, TheInfoPro’s proprietary technology indices provide tools to evaluation areas of interest to the reader.

"The organizations we interviewed have both event log management and SIEM on the top of their lists of solutions to solve their information security needs," said Bill Trussell, Managing Director of Information Security Research at TheInfoPro. "In order to fill those cyber security solution needs, security decision makers are indicating that they are selecting ArcSight’s technology as a top choice to protect sensitive enterprise information, infrastructure and operations."

About TheInfoPro

TheInfoPro is a leading advisory and research firm that provides real-world perspectives on the customer and market dynamics of the information technology landscape by using a unique research methodology that harnesses the collective knowledge and insights of leading IT organizations worldwide. Through a combination of expert advice, actionable analysis and our extensive network of IT professionals, TheInfoPro serves as a conduit between IT decision-makers, technology providers and institutional investors. Founded in 2002 by alumni of Gartner, Giga, EMC and Bell Labs, TheInfoPro is headquartered in New York City. To learn more, visit www.theinfopro.com or email info@theinfopro.com.

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)

Forward Looking Statements

This news release contains forward-looking statements, including without limitation those regarding ArcSight’s belief that, as cyber criminal attacks increase in scope and grow in sophistication, organizations are using event log management and SIEM to not only investigate attacks, but identify threats before they create problems. These forward-looking statements are subject to material risks and uncertainties that may cause actual results to differ substantially from expectations. Investors should consider important risk factors, which include: the risk that demand for our event log management and SIEM solutions may not increase and may decrease; the risk that competitors may be perceived by customers to be better positioned to help handle cyber criminal attacks; and other risks detailed under the caption “Risk Factors” in the ArcSight Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission, or the SEC, on December 9, 2009 and the company’s other filings with the SEC. You can obtain copies of the company’s Quarterly Report on Form 10-Q and its other SEC filings on the SEC’s website at www.sec.gov.

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