South Korean authorities and four security firms have disclosed a state-sponsored campaign that compromised trusted domestic websites. The attackers used those sites to exploit locally installed financial-security software and infect targeted visitors with SIGNBT or COPPERHEDGE backdoors.

A compromised page could infect a system running a vulnerable AnySign4PC version without a prompt or user-initiated download. The Korea Internet & Security Agency (KISA) says AnySign4PC versions 1.1.4.4 through 1.1.4.6 are affected and lists version 1.1.5.0 as the fixed release. It recommends deleting vulnerable installations.

AhnLab refers to two exploited products only as financial-security software A and I. Its report does not disclose their identities, affected or fixed versions, or vulnerability identifiers.