If clean out the sandbox and the files in it were partly limited and those files were malware is the pc still malware riddled after you clean the sandbox
Although I'm not familiar with Comodo's sandboxing, I think the principle is similar to other forms of containment. I'm using Sandboxie now. This essentially means that unless you have recovered an infected file or app, & already run said file outside of the sandbox, your system should remain un-exposed, unchanged, & thus safe. Deleting the contents of the sandbox flushes all un-recovered files away which should leave your system's state unchanged. Even new additions such as extensions & extracted software programs run in a sandbox should be safe. Any pre-existing infections cannot be helped by containment. I hope this helps.