The Living Daylights

Necros, Brad Whitaker and General Georgi Koskov in Tangier.
James Bond is assigned to aid the defection of a KGB officer, General Georgi Koskov, covering his escape from a concert hall in Bratislava, Czechoslovakia during intermission. During the mission, Bond notices that the KGB sniper assigned to prevent Koskov's escape is a female cellist from the orchestra. Disobeying his orders to kill the sniper, he instead shoots the rifle from her hands, then uses the Trans-Siberian Pipeline to smuggle Koskov across the border into Austria and then on to Britain.
In his post-defection debriefing, Koskov informs MI6 that the KGB's old policy of Smiert Spionam, meaning Death to Spies, has been revived by General Leonid Pushkin, the new head of the KGB. Koskov is later abducted from the safe-house and assumed to have been taken back to Moscow. Bond is directed to track down Pushkin in Tangier and kill him to forestall further killings of agents and escalation of tensions between the Soviet Union and the West. Bond agrees to carry out the mission when he learns that the assassin who killed 004 (as depicted in the pre-title sequence) left a note bearing the same message, "Smiert Spionam".
Bond returns to Bratislava to track down the cellist, Kara Milovy. He determines that Koskov's entire defection was staged, and that Kara is actually Koskov's girlfriend. Bond convinces Kara that he is a friend of Koskov's and persuades her to accompany him to Vienna, supposedly to be reunited with him. They escape Bratislava while being pursued by the KGB, crossing over the border into Austria. Meanwhile, Pushkin meets with arms dealer Brad Whitaker in Tangier, informing him that the KGB is cancelling an arms deal previously arranged between Koskov and Whitaker.
During his brief tryst with Milovy in Vienna, Bond visits the Prater to meet his MI6 ally, Saunders, who discovers a history of financial dealings between Koskov and Whitaker. As he leaves their meeting, Saunders is killed by Koskov's henchman Necros, who again leaves the message "Smiert Spionam". Bond and Kara promptly leave for Tangier, where Bond confronts Pushkin. Pushkin disavows any knowledge of "Smiert Spionam", and reveals that Koskov is evading arrest for embezzlement of government funds. Bond and Pushkin then join forces and Bond fakes Pushkin's assassination, inducing Whitaker and Koskov to progress with their scheme. Meanwhile, Kara contacts Koskov, who tells her that Bond is actually a KGB agent and convinces her to drug him so he can be captured.
Koskov, Necros, Kara, and the captive Bond fly to a Soviet air base in Afghanistan, where Koskov betrays Kara and imprisons her along with Bond. The pair escape and in doing so free a condemned prisoner, Kamran Shah, leader of the local Mujahideen. Bond and Milovy discover that Koskov is using Soviet funds to buy a massive shipment of opium from the Mujahideen, intending to keep the profits with enough left over to supply the Soviets with their arms and buy Western arms from Whitaker.
With the Mujahideen's help, Bond plants a bomb aboard the cargo plane carrying the opium, but is spotted and has no choice but to barricade himself in the plane. Meanwhile, the Mujahideen attack the air base on horseback and engage the Soviets in a gun battle. During the battle, Milovy drives a jeep into the back of the plane as Bond takes off, and Necros also leaps aboard at the last second. After a struggle, Bond throws Necros to his death and deactivates the bomb. Bond then notices Shah and his men being pursued by Soviet forces. He re-activates the bomb and drops it out of the plane and onto a bridge, blowing it up and helping Shah and his men gain an important victory over the Soviets. Bond returns to Tangier to kill Whitaker, infiltrating his estate with the help of his ally Felix Leiter, as Pushkin arrests Koskov, sending him back to Moscow.
Some time later, Kara is the solo cellist in a London performance. Kamran Shah and his men arrive during the intermission and are introduced to now-diplomat General Gogol and the Russians. After her performance, Bond surprises her in her dressing room, and they embrace.

Question: The assassin who killed what agent left a note reading "Smiert Spionam?"
Answer: agent 004