Exhibit 99.1

FireEye Reports Record Q2 Billings and Revenue and Raises 2015 Outlook

Second Quarter Billings, Revenue and Earnings per Share Exceeded Guidance Ranges Resulting in Improved Operating Leverage and Positive Cash Flow

MILPITAS, Calif. – July 30, 2015 – FireEye, Inc. (NASDAQ: FEYE), the leader at stopping today’s advanced cyber attacks, today announced financial results for the second quarter of 2015.

“Our business continued to gain momentum in the second quarter as the power of our platform resulted in expansion of our customer base, new strategic partnerships, and additional cross-selling opportunities,” said David DeWalt, CEO and chairman of the board of FireEye. “Record sales across our portfolio of network, endpoint, cloud and services offerings further highlight the power of our platform to drive growth and deliver value to customers. Our strong second quarter billings and revenue performance resulted in improved operating leverage and operating cash flow of more than $39 million, giving us the confidence to raise our outlook and accelerate our anticipated timeline for achieving positive annual operating cash flow. We achieved these outstanding financial results while increasing our investments in new products, global infrastructure, and sales capacity to extend our leadership in advanced security.”

Second Quarter 2015 Revenue and Billings

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“Demand was strong across product families, vertical markets and geographies in the second quarter, strengthening our belief that we have ‘crossed the chasm’ in advanced security,” said DeWalt. “The opportunity continues to expand, and we believe the breadth and depth of our platform positions us to extend our leadership as the market develops.”

Second Quarter 2015 Operating Performance

“Our continued focus on driving efficiency along with growth resulted in improved operating leverage and the best operating cash flow in our history,” said FireEye Chief Financial Officer Michael Sheridan. “Our results this quarter demonstrate the strength of our business model to generate operating and free cash flow. We expect our operating cash flows to be within $10 million of break-even for 2015, more than a year earlier than our most optimistic targets.”

Third Quarter and Updated 2015 Outlook

FireEye provides guidance based on current market conditions and expectations.

For the third quarter of 2015, FireEye expects total revenue in the range of $164 to $168 million. Additionally, for the third quarter, on a non-GAAP basis, the company expects:

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For 2015, the company currently expects total revenue in the range of $630 to $645 million. Additionally, for 2015, on a non-GAAP basis, the company expects:

Guidance for non-GAAP financial measures excludes stock based compensation, amortization of intangible assets, non-cash interest expense related to the company’s convertible senior notes and other non-recurring expenses. A reconciliation of non-GAAP guidance measures to corresponding GAAP measures is not available on a forward-looking basis.

CFO Transition Announced

FireEye also announced that Michael Sheridan, FireEye chief financial officer since 2011, intends to leave FireEye to accept a position as chief financial officer at a private technology company in an unrelated industry. Sheridan will remain with FireEye through the filing of the company’s second quarter Form 10-Q. Frank Verdecanna, FireEye vice president of finance, will serve as interim chief financial officer following Sheridan’s departure in early August while the company conducts an external search for a new CFO.

Verdecanna joined FireEye in November 2012 as the company’s vice president of finance with responsibility for accounting, corporate financial planning and analysis, tax and revenue operations. Prior to joining FireEye, he served as chief financial officer of Apptera, a mobile communications and advertising company, and iPass, a publicly traded global provider of mobility software and services. Verdecanna began his career as a CPA in public accounting with Coopers and Lybrand and holds a B.S. in Business Administration from Cal Poly, San Luis Obispo.

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“Mike helped build FireEye from an early-stage technology pioneer to a global leader in advanced threat protection,” said DeWalt. “We thank him for his many contributions over the past four years and wish him the greatest success in his future.”

“Frank Verdecanna is well qualified to lead FireEye’s finance and accounting organizations while we conduct our CFO search, said DeWalt. “Given his deep knowledge of our organization, I expect a seamless transition.”

Additional Business Highlights

Business highlights since the release of first quarter 2015 financial results on April 30, 2015 included multiple product releases, an expansion of the company’s ecosystem of partners, the discovery of a new zero day attack, and the completion of a $920 million offering of convertible senior notes.

Enhancements to solutions in FireEye’s Threat Prevention Platform included:

Also during this period, FireEye continued to expand its global reach and extend its technology, expertise and intelligence to new customers with:

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Conference Call Information

FireEye will host a conference call today, July 30, 2015, at 5 p.m. Eastern time (2 p.m. Pacific time) to discuss its second quarter results and updated outlook for 2015. Interested parties may access the conference call by dialing 877-312-5521 (domestic) or 678-894-3048 (international). A live audio webcast of the call, as well as related multi-media content, can be accessed from the Investor Relations section of the company’s website at http://investors.fireeye.com. Shortly after the conclusion of the call, an archived version of the webcast will be available at the same website.

Forward-Looking Statements

This press release contains forward-looking statements, including statements related to future total revenue, billings, non-GAAP gross margins, non-GAAP research and development expenses as a percent of total revenue, non-GAAP sales and marketing expenses as a percent of total revenue, non-GAAP general and administrative expenses as a percent of total revenue, non-GAAP interest expense, non-GAAP loss per share, weighted average shares outstanding, and cash flow from operations in the section entitled “Third Quarter and Updated 2015 Outlook” above, as well as statements related to the continued momentum in FireEye’s business and its threat prevention platform, the market for FireEye’s products and services, FireEye’s competitive position, the company’s belief in its ability to expand its leadership and market share gains, and the company’s CFO transition.

These forward-looking statements involve risks and uncertainties, as well as assumptions which, if they do not fully materialize or prove incorrect, could cause FireEye’s results to differ materially from those expressed or implied by such forward-looking statements. The risks and uncertainties that could cause FireEye’s results to differ materially from those expressed or implied by such forward-looking statements include customer demand and adoption of FireEye’s products and services; FireEye’s limited operating history, particularly as a public company; real or perceived defects, errors or vulnerabilities in FireEye’s products or services; FireEye’s ability to react to trends and challenges in its business and the markets in which it operates; FireEye’s ability to anticipate market needs or develop new or enhanced products and services to meet those needs; the ability of FireEye and its acquired companies to successfully integrate their respective market opportunities, technology, products, personnel and operations; FireEye’s ability to hire and retain critical executives and key employees, including a new CFO to replace Mr. Sheridan; FireEye’s ability to attract new and retain existing customers and expand and train its sales force; the budgeting cycles, seasonal buying patterns and length of FireEye’s sales cycle; risks associated with FireEye’s rapid growth; the ability of FireEye and its partners to execute their strategies, plans, objectives and expected investments with respect to FireEye’s partnerships; and general market, political, economic, and business conditions, as well as those risks and uncertainties included under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in FireEye’s Form 10-Q filed with the Securities and Exchange Commission on May 8, 2015, which should be read in conjunction with these financial results and is available on the Investor Relations section of FireEye’s website at investors.fireeye.com and on the SEC website at www.sec.gov.

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All forward-looking statements in this press release are based on information available to the company as of the date hereof, and FireEye does not assume any obligation to update the forward-looking statements provided to reflect events that occur or circumstances that exist after the date on which they were made. Any future product, feature, or related specification that may be referenced in this release is for informational purposes only and is not a commitment to deliver any technology or enhancement. FireEye reserves the right to modify future product or service plans at any time.

Non-GAAP Financial Measures

In this release FireEye has provided financial information that has not been prepared in accordance with generally accepted accounting principles in the United States (GAAP). These non-GAAP financial measures are not based on any standardized methodology and are not necessarily comparable to similar measures used by other companies. The company uses these non-GAAP financial measures internally in analyzing its financial results and believes that the use of these non-GAAP financial measures is useful to investors as an additional tool to evaluate ongoing operating results and trends, and in comparing the company’s financial results with other companies in its industry, many of which present similar non-GAAP financial measures.

Non-GAAP financial measures are not meant to be considered in isolation or as a substitute for comparable financial information prepared in accordance with GAAP, and should be read only in conjunction with the company’s consolidated financial statements prepared in accordance with GAAP. A reconciliation of the company’s non-GAAP financial measures to their most directly comparable GAAP measures has been provided in the financial statement tables included in this press release, and investors are encouraged to review the reconciliation.

Billings. FireEye defines billings as revenue recognized plus the change in deferred revenue from the beginning to the end of the period. The company considers billings to be a useful metric for management and investors because billings drive deferred revenue balances, which are an important indicator of the health and visibility of the company’s business. Revenue recognized from deferred revenue represents a significant percentage of quarterly revenue. There are a number of limitations related to the use of billings versus revenue calculated in accordance with GAAP. First, billings include amounts that have not yet been recognized as revenue. Second, FireEye’s calculation of billings may be different from other companies in its industry, some of which may not use billings, may calculate billings differently, may have different billing frequencies, or may use other financial measures to evaluate their performance, all of which could reduce the usefulness of billings as a comparative measure. FireEye compensates for these limitations by providing specific information regarding GAAP revenue and evaluating billings together with revenue calculated in accordance with GAAP.

Non-GAAP gross margin, operating margin, net loss and net loss per share. FireEye defines non-GAAP gross margin as total gross profit excluding stock-based compensation expense, amortization of intangible assets, and, as applicable, other special items, divided by total revenue. FireEye defines non-GAAP operating margin as operating loss excluding stock-based compensation expense, amortization of intangible assets, acquisition related expenses, restructuring charges and other special or non-recurring items, divided by total revenue. FireEye defines non-GAAP net loss as net loss excluding stock-based compensation expense, amortization of intangible assets, acquisition-related expenses, non-cash interest expense related to the company’s convertible senior notes, restructuring charges or discrete tax benefits. FireEye defines non-GAAP net loss per share as non-GAAP net loss divided by the weighted average shares outstanding. Additionally, weighted average shares outstanding used to calculate non-GAAP net loss per share excludes stock options, restricted stock units and performance stock units that are anti-dilutive.

FireEye considers these non-GAAP financial measures to be useful metrics for management and investors because they exclude the effect of stock-based compensation expense, amortization of intangible assets,

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acquisition related expenses, non-cash interest expense related to the company’s convertible senior notes, restructuring charges, and other non-recurring and discrete items so that management and investors can compare the company’s “core business operating results,” over multiple periods.

There are a number of limitations related to the use of these non-GAAP financial measures versus their nearest GAAP equivalents. First, these non-GAAP financial measures exclude stock-based compensation expense. Stock-based compensation expense has been and will continue to be for the foreseeable future a significant recurring expense in the company’s business. Stock-based compensation is an important part of FireEye employees’ overall compensation. Second, the components of the costs that FireEye excludes in its calculation of these non-GAAP financial measures, including not only stock-based compensation but also non-recurring items such as acquisition related expenses, amortization of intangible assets, non-cash interest expense related to the company’s convertible senior notes, restructuring charges, and discrete tax benefits, may differ from the components excluded by peer companies when they report their non-GAAP results of operations. FireEye compensates for these limitations by providing specific information regarding the GAAP amounts excluded from non-GAAP financial measures and evaluating non-GAAP financial measures together with their nearest GAAP equivalents.

About FireEye, Inc.

FireEye has invented a purpose-built, virtual machine-based security platform that provides real-time threat protection to enterprises and governments worldwide against the next generation of cyber attacks. These highly sophisticated cyber attacks easily circumvent traditional signature-based defenses, such as next-generation firewalls, IPS, anti-virus, and gateways. The FireEye Threat Prevention Platform provides real-time, dynamic threat protection without the use of signatures to protect an organization across the primary threat vectors and across the different stages of an attack life cycle. The core of the FireEye platform is a virtual execution engine, complemented by dynamic threat intelligence, to identify and block cyber attacks in real time. FireEye has over 3,700 customers across 67 countries, including 675 of the Forbes Global 2000.

^© 2015 FireEye, Inc. All rights reserved. FireEye, FireEye as a Service, Advanced Threat Intelligence, ATI, Email Threat Prevention Platform, EX, Endpoint Security, HX, PX and IA are registered trademarks or trademarks of FireEye, Inc. in the United States and other countries. All other brands, products, or service names are or may be trademarks or service marks of their respective owners.

Media contact:

Vitor De Souza

FireEye, Inc.

415-699-9838

vitor.desouza@fireeye.com

Investor contact:

Kate Patterson

FireEye, Inc.

408-321-4957

kate.patterson@fireeye.com

Source: FireEye

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FireEye, Inc.

CONDENSED CONSOLIDATED BALANCE SHEETS

(Unaudited, in thousands)

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FireEye, Inc.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited, in thousands, except per share amounts)

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FireEye, Inc.

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS

(Unaudited, in thousands)

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FireEye, Inc.

RECONCILIATION OF NON-GAAP FINANCIAL MEASURES

(Unaudited, in thousands, except per share amounts)

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RECONCILIATION OF NON-GAAP BILLINGS TO REVENUE

(Unaudited, in thousands)

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BILLINGS BREAKOUT

(Unaudited, in thousands)

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REVENUE BREAKOUT

(Unaudited, in thousands)

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