Firm’s cybersecurity unit will be split between cloud and legal departments.
Microsoft has broken up its Trustworthy Computing (TwC) unit responsible for cybersecurity at the firm for more than a decade.
A undefined number of TwC employees will be laid off as part of the plan, with the remaining engineers sent to the cloud and enterprise department while the policy team is integrated to legal and corporate affairs.
A spokesman for the firm said: "Our work on Trustworthy Computing continues to be a core commitment for Microsoft.
"We are taking some steps to move the work closer to our engineering and public policy groups, and some reductions are occurring to align our workforce."
John Lambert, general manager of network security and science at TwC, tweeted that the unit was "just moving to a new home", adding that the various functions continue to exist under "a new roof".
TwC has handled Microsoft’s cybersecurity since 2002, notably running the firm’s regular Patch Tuesday updates cycle and recently being involved in taking down a number of criminal botnets hijacking millions of computers.
Last week saw 2,100 jobs being cut from the firm as part of a significant reorganisation in which 18,000 jobs will be lost, including 12,500 from the recently acquired mobile firm Nokia.