I recently had some some memory leak issues with a .NET native crypto service provider because it's relied on unmanaged code. The only other thing I came across on SO was [this](https://stackoverflow.com/questions/1515438/which-managed-classes-in-net-framework-allocate-or-use-unmanaged-memory) post, but it didn't get in to too much detail let alone provide a good list of culprits.

Yes, if it implements IDisposable it probably uses some unmanaged resources somewhere, but I'd like to put a list together of specific classes that are commonly used instead of simply looking for Dispose in Intellisense.

The ones that I came across that caused me trouble were:

* AesCryptoServiceProvider
* ICryptoTransform

What others that rely on unmanaged resources are people aware of? Are there any especially insidious ones out there that seem like they would be completely managed but are not? Thanks in advance.