The former fruit and veg salesman, who has been twice convicted of organising the murder of his wife Arlene in 1998 using a hitman, hid the device in his buttocks from officers at his cell in Addiewell Prison in West Lothian.
Fraser received his sentence at Livingston Sheriff Court after he pled guilty of being in possession of a mobile phone illegally at the prison on October 10.
The court heard the phone was discovered when the killer turned his back on prison officers who were searching his cell and they spotted the device.
The court heard that Fraser, who is serving at least 25 years for murder, was part of a targeted search.
Stuart Houston, prosecuting, told the court three prison officers were asked to search cell 31 in the jail's Forth Charlie Wing, where Fraser is imprisoned.
Mr Houston said: "They entered the cell and saw the accused lying on his bed with no clothes on.
"He was given a dressing gown to put on, then he was asked to stand at the cell door in order to observe the search."
Mr Houston said officers asked Fraser if he had anything in his possession or in the cell which he should not have and the killer replied that he did not
He added: "The accused opened his dressing gown and was advised to put on a pair of shorts in order to carry out the search in a proper manner.
"He appeared reluctant to do so and stated he didn't have anything. He opened his dressing gown and turned round where the prison officers observed a mobile phone concealed within his buttocks."
Mr Houston said that Fraser was asked to hand over the item to which he stated he did not have anything. He added: "[Fraser] then moved to the rear of the cell where he removed the mobile telephone from his buttocks and was about to remove the phone from the cover when he was prevented from doing so."
Becky Houston, defending, said the 17-year punishment part of Fraser's life sentence had been imposed in June 2011.
Ms Houston said: "Mr Fraser has already served eight years in relation to the same matter. He fully accepts he should not have had a mobile phone in his possession and has pled guilty at the earliest opportunity."
She asked the court to take into account the length of sentence Fraser was currently serving.
Sheriff Graeme Fleming QC told Fraser: "There are good and well known reasons why mobile phones are prohibited in prison."
Mr Fleming said he had discounted the sentence from six months to four because of the early stage at which Fraser pled guilty. He added that the prison term would be consecutive to his current sentence.
Fraser recently lost his latest attempt to clear his name at the Court of Criminal Appeal in Edinburgh. He had claimed the internet had been responsible for making his trial last year unfair, with his lawyer citing the "Google factor" and arguing the trial should have been halted over trial remarks made by a cafe owner that Fraser had been in prison. His lawyer suggested this may have led jurors to carry out their own research on the internet.
After the first guilty verdict in 2003, Fraser lost one appeal then went over the heads of Scottish judges to the Supreme Court.
Legal wrangling led to a re-trial because information about the disappearance and re-appearance of Arlene's rings had not been passed on to defence lawyers.
After a second guilty verdict in May last year Fraser began the appeal process again.
Fraser may still ask the Scottish Criminal Cases Review Commission to back his fight to clear his name and could take his case to Europe.