Daniel Abed Khalife collected sensitive information between May 2019 and January 2022, prosecutor Mark Heywood told jurors at the start of the trial at Woolwich Crown Court.
Khalife, who was discharged from the armed forces after he was charged, was also accused of leaving a fake bomb on a desk before absconding from his barracks in January 2023.
He then escaped from London's Wandsworth prison in September 2023 while awaiting trial for the other charges, tying himself to the bottom of a delivery van and sparking a brief nationwide manhunt.
The 23-year-old stood trial charged with gathering information that might be useful to an enemy, namely Iran - an offence under the Official Secrets Act, obtaining information likely to be useful for terrorism and a bomb hoax.
He denied all the charges, pleading guilty during his evidence to escaping from prison, and said he wanted to be a "double agent" for the British intelligence services.
Khalife said he was a patriot and that he and his family hated the Iranian government.
"Me and my family are against the regime in Iran," he told the jury.
Khalife was found guilty of the charges under the Official Secrets Act and the Terrorism Act by a jury after more than 23 hours of deliberation. He was found not guilty of perpetrating a bomb hoax.
