This website on New Year's Eve revealed Mashaba was in talks with the National First Division strugglers to take over the reins.
Spurs CEO Freddy Mapulane has since confirmed Mashaba's appointment.
"Bra Shakes Mashaba is our new coach till the end of the season," Mapulane told KickOff.com.
Mapulane has explained why they went for the veteran tactician, who continued to coach the Nedbank Keyona Team after being fired from the Bafana hotseat two years ago for insubordination.
"Experience, father figure. In this situation you need someone who will be a father to these boys, and make them to understand that nothing is impossible in life. He is a true professional."
Asked if Mashaba will be allowed to keep his Keyona Team job, Mapulane said: "He will be full-time with us, he didn't bring that to the table. What we know [he] is our coach."
Siyavutha chairman Themba Mafu previously took control of the team in November following the firing of interim coach Vusi Mkhatshwa and exit of Sammy Troughton, who had replaced Zimbabwean coach Rahman Gumbo.
Spurs are bottom of the second-tier table with 12 points from 15 games, and will resume their fight for survival against Cape Umoya United at home on Saturday (15h30).