In the PC version of Counterfeit, there are a number of Left 4 Dead action figures in the childrens room in Mitchell's house.
In First world bank there is a chance the AI (after or before an assault) will jump on the table and start talking to hostages. What they say is a quote from the movie Heat.
The painting in the meeting room of the First World Bank depicts Team 7200, the first team to get inside the secret "Overvault". The painting of them was added through a patch. There is a 30% chance the painting will have changed, in addition to there being some creepy music heard from a nearby CD player and lit candles being on the table. The patch also added two plaques in the vault that have the names of the people who helped find the secret.
Many of the heists in the game take inspiration from movies such as Heat (Heat Street), Inside Man (First World Bank) or Panic Room (Surprise Panic Room).
A YouTuber named 'UberHaxorNova' noted the size of an abnormally large toothbrush on a bathroom floor in the game. The developers, upon seeing his video, updated the game to include a gigantic toothbrush the size of a broom in place of the older one.