They are the most feared and ruthless terrorist organiations currently existing with thousands of foot soldiers working with sophisticated weapons. So who and who is on the list?

1. ISIS

Also known variously as ISIS, IS, ISIL the Islamic state is the world’s current number one terror organisation.

Islamic State (ISIS) militants are taking in more than $3m (£1.8m) a day through oil smuggling, extortion, theft and human trafficking, say intelligence officials and experts. They now control several oil fields in Iraq and also make money from extorting cash through kidnapping.

ISIS are the baddest guys in terrorism! They are worth a whooping $2 billion.

2. The Irish Republican Army (IRA) - $450 million

The IRA is regarded as a top professional money laundering organisation. The group first started as a revolutionary force fighting Britain for Irish Independence and is now regarded as a terrorist group for the countless bombings and assasinations attributed to them during the revolt against British rule.

3. The Taliban ($400 million)

The Taliban is a famous terrorist organisation in Afghanistan, they make their money from drug trade, human trafficking, kidnapping/extortion, and even donations from sympathetic groups. The Taliban are responsible for a huge opium production operation in Afghanistan that heavily contributes to an estimated $70-$400 million that they rake in annually from illicit drug trade alone.

4. Al Qaeda ($100 million)

The Al Qaeda network became known all over the world after the notorious 9 11 bombing. At a time it was the world’s richest and most powerful terrorist organisation. Suicide bombing was one of their most favourite tactics; in fact they made suicide bombing become a popular terrorist tactic.

Osam Bin Laden, its leader (who was killed in a US covert mission in Afghanistan) became the most wanted man on earth after the September 11 bombings in the United States. Osama Bin Laden was already a multimillionaire when he founded Al Qaeda. Al Qaeda is known to have widespread terrorist allies all over the world.

Full list: Nairabrains World's richest terrorist groups