Microsoft server hack likely single actor, thousands of firms now vulnerable, researchers say

Hack exploits previously unknown flaw in SharePoint software

Thousands of entities potentially now vulnerable to attack

Hack likely work of one threat actor or group, researcher says

Unclear who is behind attacks

LONDON, July 21 (Reuters) – A global attack on Microsoft server software used by thousands of government agencies and businesses to share documents within organisations is likely the work of a single actor, a cybersecurity researcher said on Monday. Microsoft on Saturday issued an alert about “active attacks” on SharePoint servers used…