It sounds like it was an old school PBX style attack, and making use of voice bridging type features to make calls via business lines. This style attack has bee

It sounds like it was an old school PBX style attack, and making use of voice bridging type features to make calls via business lines. This style attack has been around for a long time, and quite frankly isn't really hacking in most cases - generally the systems are using default passwords, or it can also be a social engineering style attack via the operator/secretary of such systems.