these people are wrong. it only contains the ILLUSION of being a png file. it is NOT a png, it IS an executable, it IS a virus, it WILL infect you, it WILL steal your SL account lindens, and payment information. i am a computer technician who specializes in repair and anti-malware. filename extension spoofing is not difficult. i have seen the file, as a friend who was infected by this brand new virus, attempted to send it to me. it is a faked png, with an executable icon.
i repeat. anyone who has 'checked out the file' and thinks its clean, that is because they only used an antivirus that has not picked up this newly-written virus. do not accept it, download it, run it, or underestimate it.
and the reason google doesnt pick it up is because every time the virus deploys its payload, it randomly generates a new filename: the alghorythm is: Snapshot(orIMG)_######CCCCC.png(.hidden exe) thats 6 randomly generated numbers, 4 or 5 letters, followed by .png, followed by its hidden executable extension.