Two gunmen riding a motorbike targeted General Mohammed Said, head of Ibrahim's technical office, as he left his home, located close to government buildings and a police station, the interior ministry said in a statement.
Egypt has witnessed a surge in attacks by Islamist militants in Cairo, the Nile Delta and the volatile Sinai Peninsula since the military ousted former president Mohammed Morsi last July amid widespread protests against his rule.
Four bombs exploded in Cairo the day before the third anniversary of the January 25 revolution, including one at the capital's main police headquarters. The blast killed six people and damaged the nearby Islamic Museum.
Egyptian troops killed a leader of an Al-Qaeda inspired militant group based in Sinai that claimed a failed attempt on Ibrahim's life in September and the murder of a high-level security official in recent months, Al-Ahram reported in mid-December.
Ansar Bayt El-Maqdis has claimed responsibility for most of the recent spate of attacks, including a military helicopter crash in North Sinai on Saturday, the shelling of a camp there and an attack on three security checkpoints on Sunday in which a soldier died, according to daily Al-Masry al-Youm's website.