The Qakbot botnet has been disrupted by an international law enforcement operation that culminated last weekend, when infected computers started getting untethered from it by specially crafted FBI software. Arranging a widespread Qakbot removal The Qakbot administrators use a system of tiered servers (Tier 1, Tier 2, and Tier 3) to control the Qakbot malware installed on infected computers.

Source: Help Net Security