Gray gear icon, same as in Wikipedia (and certain other Wikimedia projects) interwiki section. It is intended for use in the Russian Wikipedia navboxes, so it's a little darker than the actual icon.
Universal Language Selector extension of MediaWiki, https://github.com/wikimedia/mediawiki-extensions-UniversalLanguageSelector/blob/master/resources/images/cog-sprite.svg
Wikimedia Foundation; Santhosh Thottingal &lt;santhosh.thottingal@gmail.com&gt; (according to File:Cog-ULS-gear-latest.png); 

Alolita Sharma
Amir Aharoni
Arun Ganesh
Brandon Harris
Niklas Laxström
Pau Giner
Santhosh Thottingal
Siebrand Mazeland [1]