Library genesis has a standards section, although for some reason it's spelled "standards". And it's not that standard-rich.

For now Google seems to do the standard-pirating job better, partly because it indexes Baidu's Wenku ;)

A quick look shows libgen saying “standards” (the correct spelling) in multiple places. The URL, OTOH, says “standarts” (note the “t”)

IsoHub.org belongs to Cuba.

StandardsHub.org is occupied by ISO

IEC, ISO and BS standards compilations are are all over the torrent sites.