Not Now...But Never Say Never
First let me say that anything involving technology is possible. In today's world of ever changing and evolving high tech systems no one can say with complete certainty that the infection of a Smart TV is impossible. Back in the 1960's the idea of a hand-held two-way communication device that could fit in the palm of your hand (today called the cell phone) was pure science fiction. Anyone remember the original Star Trek series communication device ("two to beam up - Kirk out")?
As others have said a virus and/or malware are for the most part specific to a computer OS (i.e. Windows, Mac, Linux). Of late however, there are indications that iOS and the Android platforms are becoming targets of interest. Having acknowledged the threat to those platforms one must remember what a virus or malware is designed to do....and that is...to exploit known vulnerabilities and/or create new ones for the purpose of obtaining information and/or redirection or monitoring of a computing system via input commands.
So ask yourself...as Smart TV's exist today (or in the foreseeable future) how much information of worth is stored (or capable of being stored) on them? What profit would one gain from being able to control the commands input via a TV remote control (given...at present...there is no information of worth to exploit)? Granted there are a few Smart TV's with built-in webcams so there's the possibility that code could be written to turn it on remotely to monitor your movements (voyeurism) or inventory your home. Here again we're dealing with a high degree of speculation versus real world documented events. The algorithms to accomplish what I just mentioned would have to be very sophisticated and hardly worth the time as the ROI would be zero to none as things are today.
In practicality, writing code to exploit a Smart TV (today) has little to no value for a would-be assailant. Engineering code to infect your computer or network via your TV is counter productive versus writing code to infect the more readily available and desirable computer hard drive (a more direct approach). A DVR would qualify as a more desirable target than your Smart TV as most have a considerable amount of hard drive space capable of hosting a malicious threat.
Now...having said there's nothing to worry about...let's not dismiss the possibility as completely absurd. Ocean Blue Software in collaboration with Sophos has developed a cloud based anti-malware system called "Neptune" designed to protect digital content on connected TV's. The question is whether or not the content providers and/or the set manufacturers will buy into the concept as a needed form of protection against today...what is a relatively an unverified threat. You can read more about Neptune via the following link:
In closing do you need an anti-virus specific for your Smart TV the answer would have to be IMO "no" at this juncture. Besides...who makes one and how would it be deployed? Do you need an antivirus to protect your computer ...the answer is a definite "Yes"!
I hope this brief writing along with opinions provided by other members has answered your question. If you have additional information (verification or documented occurrences) regarding your topic please post it. I think this is a very interesting subject that could stir substantial debate in the not so distant future.
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