» Bob West (left) has joined CipherCloud, a San Jose, Calif.-based cloud security firm, as chief trust officer. West has previously served as the CISO at Fifth Third Bank and Bank One, as well as a manager with Ernst & Young‘s Information Security Services practice in Chicago, and a senior systems officer with Citicorp.

» Blackstone, a multinational private equity firm in New York City, has acquired Accuvant, a Denver-based security services and solutions provider. The deal, reported to be worth $225 million, gives Blackstone 80 percent ownership of the 12-year-old security company, while Accuvant executives hold on to 10 percent of shares. Blackstone bought a majority stake in Accuvant from investment firm Sverica International, which will retain a minority stake under the agreement.

» Alex Stamos has joined Sunnyvale, Calif.-based tech giant Yahoo as vice president  of information security. He will be tasked with leading all aspects of information security including the company’s “Paranoids” team. Prior, Stamos co-founded iSEC Partners and served as CTO of Artemis Internet. More recently, the security expert co-founded and hosted TrustyCon, a one-day security conference that occurred in late February. At Yahoo, he will report directly to Jay Rossiter, the company’s senior vice president of platforms and personalization products. 

» Steve Bennett, president and chief executive officer of security firm Symantec, was terminated by the company in March. The move makes Bennett the second CEO that Symantec’s board of directors has pushed out in the last two years. Prior to hiring Bennett, former CEO Enrique Salem was terminated at the behest of the board. Michael Brown has been named the interim president and CEO at Symantec as the company searches for a permanent replacement. 

» Tufin Technologies, a provider of security policy orchestration solutions, has added two new executives to its team. Ed Greene (left) has joined the company as chief revenue officer, while Jack Wakileh was appointed as chief financial officer. Greene will be responsible for streamlining sales processes and implementing best practices, while Wakileh will be tasked with managing global financial operations, policies and planning. 

» Palo Alto Networks, a network security provider, has acquired Cyvera, a privately held security firm in Tel-Aviv, Israel. Under the deal, Palo Alto will purchase Cyvera for $200 million. Cyvera employs a staff of 55 and offers enterprise solutions to thwart zero-day attacks on the endpoint. With the acquisition, Palo Alto expects to enhance its automated detection offerings to defend customers from advanced threats facing their organizations.

» Lockheed Martin, a Bethesda, Md.-based security and aerospace company, has acquired Industrial Defender, a provider of security solutions for control systems in the oil and gas, utility and chemical industries, which is headquartered in Foxborough, Mass. With the acquisition, Lockheed Martin expects to expand its suit of technology and services for enterprise clients, particularly those that manage or protect critical infrastructure.