You can find the press release from the Department of Justice announcing the two Iraqis' sentencing here.
Two Iraqi citizens living in Bowling Green, Ky., who admitted using improvised explosive devices (IEDs) against U.S. soldiers in Iraq and who attempted to send weapons and money to Al-Qaeda in Iraq (AQI) for the purpose of killing U.S. soldiers, were sentenced today to serve federal prison terms by Senior Judge Thomas B. Russell in U.S. District Court for the Western District of Kentucky.
You can also view the archived press release put out by the FBI when the two individuals were charged here.
From an ABC News story published November 2013:
As a result of the Kentucky case, the State Department stopped processing Iraq refugees for six months in 2011, federal officials told ABC News – even for many who had heroically helped U.S. forces as interpreters and intelligence assets. One Iraqi who had aided American troops was assassinated before his refugee application could be processed, because of the immigration delays, two U.S. officials said. In 2011, fewer than 10,000 Iraqis were resettled as refugees in the U.S., half the number from the year before, State Department statistics show.
From Has America Abandoned an Afghan Interpreter? - The New Yorker, 23 Sept 2013
He couldn’t have known that in February, 2011, the entire S.I.V. program had ground to a halt in Washington, because two Iraqi refugees in Kentucky—neither had had anything to do with the Americans in Iraq—were arrested on terrorism charges. The issuance of visas to Iraqis and Afghans who were already as thoroughly background-checked and fingerprinted and retina-scanned and polygraphed as any applicants in the world, and who had already passed up numerous chances to kill Americans in their own countries, stopped. The White House, the State Department, Homeland Security, and the intelligence agencies tried to come up with a new vetting formula. The interagency gears barely moved. Shinwari waited a year, two years.
I believe the existence of plenty of secondary sources indicate that yes, the Obama administration did halt processing of visas for Iraqi refugees for a period around 6 months in 2011 after evidence had showed that mistakes had been made in how the refugees were being processed. I was not able to find any information from the State Department itself on exact dates for when it began and when it was lifted.
Note: The claim is: processing was halted for Iraqi visas under the Obama administration. My interpretation is that if someone decided to not process Iraqi visas for a given day, that qualifies as a halt to processing. If such a halt itself lasted for a day, I could understand that it could cause a delay in an individual's visa process that is longer than a day. If the halt lasted for around 6 months, it could have caused individuals (such as the one mentioned in the New Yorker) to be delayed for much longer.
Secondary sources published two years later describe it as lasting about 6 months, and does not seem to have ever been referred to as a ban, but that is not what is being claimed.