He gets free accommodation, meals and weekly benefits and plans to bring over his wife and two children.
Aabouss, who claims to be a 31-year-old interior designer from Aleppo, told The Sun: “I was desperate to get here but amazed they let me in.
“If it was that easy for me imagine how easy it would be for a terrorist with more finances and more sophisticated methodology.”
Hundreds of illegals are feared to have flooded in last year using the same trick.
New MI6 chief Alex Younger has warned the next UK terror attack is likely to “emanate” from Syria.
David Burrowes, MP for Enfield Southgate, called for an investigation.
He added: “We cannot leave the door open to the UK — not to migrants and especially not to terrorists.”
Fellow Tory Philip Davies added: “The Home Secretary needs to get a grip.”
Dover MP Charlie Elphicke added: “This shocking case underlines how desperate people will do anything they can to break into Britain.”
Aabouss fled the civil war before Christmas 2015.
He and his family travelled to northern France but were marooned at the Jungle.
He said: “I couldn’t face another winter in a refugee camp, even though the Jungle is now closed.
“We decided I had to get to the UK, seek asylum then get my family here too.
“I hated breaking the law but could see no other way.”
With just £500 to his name he approached smugglers for a passport.
But to my great surprise the smuggler said he’d got me a special price, £300.
“I looked at the passport owner’s photo. He looked similar to me with the same short brown, thinning hair and light skin.
“The only problem was he looked ten years older.
“But I was desperate so I handed over the money.
“The man advised me to go to Germany then fly to the UK because few migrants used that route.
“I spent the rest of my savings on a rail fare to Dortmund and Ryanair ticket to Stansted.”