That's rather vague...
Do you have an example of the malformed link vs. actual? Did you run an Email Link report?
If you are asking "Can I search all my emails for a URL?" the answer is no. I believe there's an Idea for it.
I have this same question. I am looking at the Email Link report for a specific email that we sent. It lists all of the links in the email, but at the end it has "Malformed Link" in the Link column, with a number of clicks and a number of leads. How do I know which link is causing the issue?
I found this post which explains what causes a malformed link. This makes it seem like any of the links could be recorded as malformed due to an issue on the client side, and that the result is that Marketo doesn't know exactly who the click is associated with. But that doesn't explain why those malformed link clicks would be represented on one separate line in the report, and not associated with any specific link. Shouldn't Marketo still be able to attribute the click to a specific link, whether or not it knows who clicked?