This is one of many short animated clips contained within the 2002 eroge game Viper-RSR from the now-defunct Japanese game company Sogna. (According to Wikipedia, Sogna’s games generally featured “young Japanese girls who, in one way or another, find themselves either kidnapped or attacked by monsters, cyborgs, or aliens.”) You can find an extensive gallery of additional Viper-RSR clips at the Ecchi Archive.
Image provenance by Bacchus at Erosblog.