A computer code that is supposed to be able to infect DNA was found.
The corresponding article posted ~2.5 years, and some c++ codes.
So could there really be a computer virus that infects DNA?
Virus code is here: http://pastebin.com/NiQc55rr
It is NOT impossible for a computer virus to infect real DNA because 'artificial' life was already created from synthetic DNA by Craig Institute. Proof. That synthetic DNA coming from files that were generated in a computer. So, if the virus happens to be in the right computer, at the right time... But the chance is small.
However, in the next 10 years, that virus might be a real problem as every year it is more and more easy to create 'artificial' life.
I have found this comment in the C++ code:
// Encode own file into Craig Venter's DNA encoding languageIt looks like this virus was designed expressly for Craig Venter! So the chances for this virus to work (affect real-world DNA) are even more realistic!!
Validity of the code
Less experienced people doubt the validity of the code. However, no proof was brought to demonstrate that the code might fail (and why). Though, I haven't spend hours to read the code line by line and thoroughly analyze it, I did pick a look at it and it seem sound and valid. The fact that the author of the code targets a very specific organization (that "happens" to generate DNA from computer files) tells us that he knows what he is doing.
As somebody already brought to our attention, there is no purpose in creating this virus. But this is totally irrelevant to the original question. Even if the DNA virus will destroy the host cell and even if it won't be able to replicate in real world (and it won't) it is irrelevant. If in the right computer, the computer virus will pass from the virtual world to the real world, and this is OP's question (I think).
The question asked was: "can a computer virus could infect DNA"?. The question is ambiguous. If it refers to the DNA of some living cell the answer is no. HOWEVER, if the question refers to a human-created cell, the answer is YES. Craing Venter creates DNA from computer ('fasta') files. If one of those files happens to be modified or 'infected' by the computer virus then the computer virus will have effect in real world (the DNA synthesized by Venter will contain the code injected by the computer virus).