You don't need to modify existing analysis programs. I worked on a Cloud Genomics product and we inspected BAM parsers, etc, and they all lack basic validation, so it's trivial to create malicious inputs that cause them to crash.
When we filed bugs against the products, the reply was that security was not a priority, because academics.
These kinds of parsers often run on machines that have a great deal of valuable intellectual property on them. It's not unreasonable to believe that somebody might exfiltrate IP from a biotech using malicious DNA sequences. It's unlikely, but not unreasonable to believe.