Windows XP flaws help Russian ‘Qbot’ gang build 500,000 PC botnet

The Russian gang behind the obscure Qbot botnet have quietly built an impressive empire of 500,000 infected PCs by exploiting unpatched flaws in mainly US-based Windows XP and Windows 7 computers, researchers at security firm Proofpoint have discovered.

A year or two ago, what the Qbot (aka Qakbot) campaign has achieved in the roughly half dozen years the actors behind it have been operating would have been seen as a major concern. Recently, standards have gone up a notch.