The Justice Department prosecutes all crimes prosecuted by the U.S. federal government regardless of which agency has jurisdiction over that kind of regulatory activity.
The Canadian government could prosecute for passport fraud or forgery.
The offshore account country could prosecute for bank fraud or forgery.
The U.S. federal government, the Canadian government, and the offshore jurisdiction could probably all prosecute for attempted money laundering or attempted tax evasion (or worse, such as attempted material support of terrorism).
Realistically, none of this is terribly likely to happen if there is no harm, and even if there was an arrest and a conviction, the sentence would probably be mild for such a victimless white collar crime (probably probation and a fine or a few months in jail at most unless there were larger aggravating factors). But, harm is not required for a criminal prosecution. Or, more precisely, the violation of the criminal law per se is the harm.
18 U.S.C. § 1543 states:
Whoever falsely makes, forges, counterfeits, mutilates, or alters any
passport or instrument purporting to be a passport, with intent that
the same may be used; or
Whoever willfully and knowingly uses, or attempts to use, or furnishes
to another for use any such false, forged, counterfeited, mutilated,
or altered passport or instrument purporting to be a passport, or any
passport validly issued which has become void by the occurrence of any
condition therein prescribed invalidating the same—
Shall be fined under this title, imprisoned not more than 25 years (if
the offense was committed to facilitate an act of international
terrorism (as defined in section 2331 of this title)), 20 years (if
the offense was committed to facilitate a drug trafficking crime (as
defined in section 929(a) of this title)), 10 years (in the case of
the first or second such offense, if the offense was not committed to
facilitate such an act of international terrorism or a drug
trafficking crime), or 15 years (in the case of any other offense), or
This statute clearly applies to both U.S. and non-U.S. passports. But, it isn't obvious that the crime would apply in this case, because the crime may have taken place outside the U.S. and with a target outside the U.S., one or the other must be true for the U.S. to enforce its criminal laws - U.S. citizenship isn't sufficient.
The offense in this particular statute is making with the intent that some use it, using or attempting to use a passport. The crime was directed at the offshore location. But, it wouldn't be such a stretch to assume that if the fake passport was made or used by the defendant in a U.S. living room that it was used there even if only to send it over the Internet to a foreign country. On the other hand, if the fake passport were made or used in a hotel room in Montreal by a U.S. citizen and was directed at the Cayman Islands, the U.S. might lack criminal jurisdiction over the case.
The maximum offense would be 10 years and a fine for a first or second offense, but the U.S. Sentencing Guidelines would very likely call for a much milder recommended sentence, and any excess punishment over this recommendation would have to be justified by the judge.