The players whose computers were compromised are the obvious victims, but they may not be the only ones affected.
If an attacker could view a compromised player's hole cards while they were playing, opponents sitting at the same tables could potentially have been exposed to an unfair information advantage.
There is currently no complete public list of affected games or evidence establishing how many opponents may have been impacted. It is therefore too early to put a number on the wider damage.
The incident does, however, highlight a broader security issue for online poker.
Third-party software has become a normal part of the modern online poker setup. When trusted tools are compromised, the potential consequences can extend beyond the player who installed them.
For Canadian players using third-party poker software, the incident is another reminder that securing the poker client itself may not be enough. The software running alongside it also has to be trusted, and one weak link can ruin it for everybody else.