It’s no longer seen as a market leader, its share price has been in the doldrums and it doesn’t even make that much money. No surprise that commentators are taken aback at Intel’s sudden splash on the security industry’s perennial number two, McAfee.

What is Intel buying that it couldn’t simply license for a fraction of the price and risk?

You could do worse than look at the companies McAfee has bought in recent times to get a flavour of what McAfee has become beyond its well-known antivirus stable.

McAfee’s purchases turn out to have all been worthy attempts to diversify away from selling simple security software, taking in email security services (MX Logic), data loss prevention (Reconnex), encryption and management (Safeboot), and only this year, smartphone security (Trust Digital and TenCube). Further back, it bought sometimes misfiring web reputation software in the form of SiteAdvisor.

The big one was probably the purchase of Secure Computing, noted for its range of security appliances based around security baked into chip-level designs. It is being said that Intel wants to embed security to bolster processor designs of the future, which makes Secure look like a key part of what is being bought.

But McAfee paid $465 million for Secure less than two years ago so is there really an extra seven billion or so of value in McAfee now?

Perhaps the bigger attraction is McAfee’s move into security services (SaaS), which means not only filtering but, more recently cloud assurance services such as the McAfee Cloud Secure Program. This fits with the view that Intel wants to build a portfolio of underlying technologies around super-secure embedded mobile chips tied to a cloud security platform (also running its chips).

The integration work that McAfee has done in recent years would take Intel a while to assemble on its own, so buying McAfee saves it important time. That bumps the price up a bit, although Intel + McAfee is still a long way from being some kind of cloud superpower. Mobile security is still in its infancy mainly because the threats barely exist.

Perhaps Intel is buying McAfee for the same reason that a number of security companies have been bought in recent times. The buying company looks at its stable of successful products, realises it lacks on security expertise and IP, and looks around for a company at the right price.

Given that Symantec is far too massive to buy at all, McAfee (whose stock price has traded at well over $40 in the recent past anyway) is actually an affordable way of adding some security gloss.

But perhaps the real point of buying mature security companies is the engineering expertise and intellectual energy that arrives with the acquisition, the chance to infuse a company set in its ways with some new blood. That is what McAfee got for all its money in buying startups and it is now a much more varied and energetic company than many people realise.

Marooned on a profitable but unsteady island of X86, Intel badly needs some of the same. If it gets this, the billions will have been cheap at the price.