Apple’s market share of the world PC market has reportedly hit a 15-year high, according to an analyst note from Needham and Co., GigaOm reported.

The company now holds about 5.2 percent of the worldwide market, growing 24.6 percent in the past year. Compared with the overall market’s 5.3 percent growth in the past year, that makes Apple look very good, indeed.

According to the note, Apple saw PC growth in almost every sector — except for government purchases — taking on larger chunks of the enterprise market.

As GigaOm’s Erica Ogg points out, analyst firm Forrester recently encouraged businesses to let employees use their Macs from home for work because of their “reputation for reliability and low maintenance.”

As Apple gains a larger part of the market, however, Mac users will also likely keep a sharper eye out for malware and viruses Right now, the company’s relatively small slice of the market has kept it mostly insulated from the threat of malware, though Mac OS X was hit with a fairly big attack earlier this year. It’s a good reminder for Mac users that it never hurts to be cautious.

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