Also: DOL won't block MCI stock buy; HP fires three execs; most spam comes from the U.S.; Minnesota teen admits to spreading Blaster; and moreIBM\u00a0last week said it's hiring a lot more employees than originally planned. The vendor boosted its forecast for the year from 10,000 up to 18,800 new hires, two-thirds of whom are destined for IBM's global services division. Driving the hiring spree is growth in areas such as\u00a0Linux\u00a0services, grid computing and business transformation services. The most popular position being filled is consultant, followed by IT architect, software engineer, sales staff and project manager. IBM expects to close the year with more than 330,000 employees - its largest head count since 1991, when the IBM population topped 344,000.The Department of Justice will not stand in the way of Leucadia National if it decides to buy at least 50% of\u00a0MCI's\u00a0stock. Last week the federal government let a deadline pass without action, essentially letting the companies move ahead with any stock purchase plans. Leucadia, a holding company, sought permission in July to purchase at least 50% of MCI's stock. But at press time Leucadia has yet to make a formal offer to take over MCI or buy a large chunk of the company's stock. If Leucadia does start a hostile takeover bid, MCI can activate its "poison pill." In April the company adopted a Shareholders Rights Plan, which lets MCI make common stock available to its shareholders at a reduced price if another company acquires more than 15% of MCI's stock. This would make the acquisition more expensive for the acquirer.HP\u00a0fired three major sales executives last week, including former server group head Peter Blackmore, in a management shakeup after a disappointing quarter for HP's server division. Blackmore was executive vice president of the Customer Solutions Group, which was formed last December to manage direct sales to enterprise and public sector customers worldwide. Jim Milton, CSG senior vice president and managing director of the Americas region, and Kasper Rorsted, CSG senior vice president and managing director for the Europe, Middle East and Africa region, also were dismissed. Chairman and CEO Carly Fiorina announced the changes in an e-mail to HP's employees, which was then sent to the media. HP's Enterprise Servers and Storage Group suffered through a painful second quarter, Fiorina said in HP's second-quarter earnings conference call. (See more on HP's plans, click\u00a0here.)Almost 86% of\u00a0spam\u00a0sent to 1,000 corporations between May and July came from U.S. spammers, according to a survey by e-mail security tools vendor CipherTrust. While U.S. IP addresses made up only 28% of the spam-sending addresses in CipherTrust's survey, those U.S. addresses sent out more unsolicited commercial e-mail than spammers from other nations, according to the company. In contrast, nearly 29% of the IP addresses sending out spam during the three-month survey were in South Korea, while only 3% of the spam came from there. The survey, which sampled about 5 million pieces of spam sent to 1,000 CipherTrust customers, runs counter to some other surveys and some critics of the CAN-SPAM law, who suggested a U.S. law would have a limited effect because of the amount of spam that comes from outside the U.S.A19-year-old pleaded guilty in a Minnesota federal court on last week to spreading the W32.Blaster-B worm over the Internet. Jeffrey Lee Parson of Hopkins, Minn., said he was responsible for creating and unleashing the worm, which affected thousands of computers worldwide. He faces one count of intentionally causing or attempting to cause damage to a protected computer in connection with the release of the worm. Parson could face between 18 and 37 months in prison and pay millions of dollars in fines. Sentencing is scheduled for Nov. 12. Parson was tracked down last year by a joint federal task force that involved members of the FBI and the Secret Service.Art Technology Group last week announced plans to acquire Primus Knowledge Solutions in an all-stock transaction valued between $30 million and $33 million. ATG makes e-commerce and marketing software aimed at companies in business-to-consumer industries. Primus offers knowledge management tools, including content management and search technologies, and Web self-service tools for customer service. The pairing of e-commerce and CRM technologies makes sense, and ATG has been working to add marketing and customer self-service to its lineup, says Ian Jacobs, a principal analyst at Current Analysis.