There are different levels of cooperation in evil, and each one has a different degree of culpability.
First, there is formal cooperation in evil. That is when you deliberately, consciously, and willingly intend the evil to happen. Civil law calls it being an accessory to a crime. If you know a murder is going to happen, you say or do nothing to prevent it, and you really want it to take place, that is formal cooperation. There is knowledge of the evil beforehand or while it is happening, and consent to it being done. This is always sinful and immoral.
Material cooperation in evil is when you provide the means for the evil to be done. Supplying weapons to criminals, giving alcohol to minors, lying to the police to provide an alibi for a suspected criminal, these are all examples of material cooperation. You did not commit the act itself, but you helped make it possible by providing material cooperation.
Moral theologians also further subdivide material cooperation into two more categories: proximate and remote. Proximate material cooperation would be giving or selling weapons criminal groups. You are directly giving material cooperation without which the evil could not be done. Proximate material cooperation requires the level of necessity; your assistance was necessary for the crime to take place. Providing proximate material cooperation while withholding formal cooperation is still immoral and sinful. You can’t say “I am personally opposed to abortion” but then provide someone the money or transportation to get one.
Remote material cooperation is further down the line and often can indicate no culpability, or at least a reduced level. Buying stolen goods is remote material cooperation, and it is immoral if you are aware that the items are stolen. If you are scammed by a con artist and unknowingly buy stolen goods, your guilt is minimal to nonexistent, depending on whether or not it would have been possible to ascertain if the items for sale were stolen.
The more remote the material cooperation, the less the culpability. Buying confiscated cars and homes from the police that were seized from drug dealers is permissible. Even though you know the property was obtained through illegal and immoral means, your purchase is not going to encourage further criminal acts.
Obviously, if force is used to coerce you to provide material cooperation, then by withholding formal cooperation (not giving internal consent to what is being done), your culpability is also greatly reduced.