Israel has accomplished something like this before - they managed to slip thousands of ordinary-looking, fully functional but sabotaged high-voltage electrical connectors into a shipment bought/used by terrorists to build rockets. The installed-connectors caused the rockets to detonate, crash or burn up when launched. 

It took some time for the terrorists to figure out why their rockets kept exploding/crashing, so they kept launching them for some time after the first one, with the same catastrophic results. They apparently didn't figure out what happened until it had already cost them tens of millions of dollars and many friendlies killed/wounded. 

Not too long ago the Mossad is thought to have inserted agents into Iran to build a bomb into the walls of a VIP safe-house, which was used to assassinate the leader of Hamas when visiting Iran. The Iranians likely lied to cover their humiliation at such a spectacular failure of internal security by releasing a statement claiming the assassination was done using a mobile rocket-launcher. heh That's less-humiliating then the truth, apparently.

The damage to morale of the Iranians and their savants in this latest triumph for Israeli intelligence, is far greater than the actual material losses inflicted. It no-doubt leaves them shaken, not stirred.