Of those surveyed by NOP on behalf of the Business Software Alliance, 55% said mobile and remote working was making it increasingly difficult for them to know what their staff are loading onto laptops and mobile devices.
The survey also found that 67% of managers were not concerned about the potential problem.
The BSA, which protects suppliers' software copyright, warned this lax attitude towards potential unauthorised software use could leave firms open to legal action.
The BSA said IT management policies and processes that companies implement within the office environment may not be enforced for staff working remotely or on the move.
Siobhan Carroll, BSA regional manager, said, "Organisations need to keep a tight reign on exactly what their staff are putting onto their mobile devices. This research suggests that UK managers have a dangerously lax attitude to the downloading of illegal software on company devices."