Having escaped from both Francoist Spain and subsequently the French Government’s internment camp in 1940, he began to put his artistic talents towards a new project: forging the passports and ID cards necessary to allow Spanish fighters to move throughout occupied France and back into Spain.
In the words of Jorge Semprún, a fellow Spanish Communist Party (PCE) activist:
"So many of us owe our freedom to [Malagón], and some of us our lives. Sometimes I saw him working, almost lovingly handling the inks, the stamps, the plastics and colours [...] The documents would turn into works of art, comradely safeguards for the possible storms of clandestine life."
Working from a secret workshop in Paris provided to him by French resisters, Malagón would spend up to two weeks on each document. Leaders of the PCE such as Jesús Monzón would use his papers to travel throughout France, organising resistance in the Spanish labour camps and liaising with their French counterparts. Malagón would continue to forge identity documents for activists within Spain until the death of Franco some thirty years after the war ended.