Of course this is the same way the Sagger worked that the NVA were using against us. However the US Army told the South Vietnamese that the Sagger was heat seaking. As a result of this, the ARVN started throwing flares out when ever they saw the big black lauch cloud meaning a missile was on its way. They would also fire in the vacinity of the cloud since the control cable was only a few feet long meaning the gunner had to be nearby. As a result, the NVA gunner would have everybody shooting near him and as he looked through his sights, he would see several flares burning. “Which was his???” The counter measures worked for all the wrong reasons.
White phosphorous smoke works well, too, as the missile flies through the smoke WP particles have a good chance of burning through the control wires, and anything that obscures the operators view of his missile is an improvement.
It's not just the NVA who used the Sagger, aka the 9M14M Malyutka, however.... and they make a very nice job of a BRDM armored car, as you might expect.