This is an interesting question, and it's fun to see what other people use for their 'placeholders'. To answer your question, I'm not aware of any 'standard' fake company.
I would suggest evaluating your user interface to ensure the user understands what a company or product really is. How can you achieve this? Using consistent language throughout the product is one way, as well as ensuring the language used fits the target audience. If I, the user, understands fully the purpose of entering a company and product then I don't really need an example to get the task done. However, if this is my first introduction to the concept then it'll be harder to understand. It depends on context here a lot, so more info would be helpful.
If you really have to go with an example, I'd use your own company, depending on the context of that. Any other company is a subtle promotion, and a fake company may not actually achieve the desired effect. If I see,
E.g. you can enter "Ventoice" and "Urteltron"
that doesn't actually provide me with any information.
In summary, it depends on your context. If your users are casual, you can probably get away with a well established TV-show joke. If you're doing serious work, this might not fly. Instead of relying on the examples, I'd recommend supporting the interface with enough background information and relevant language to teach the user enough so that they don't need examples. Good luck!