A colossal cyberattack on Tuesday has been wreaking havoc on countries and corporations across the globe, and some cybersecurity experts are zeroing in on a familiar name as the possible culprit.

The attack, dubbed “Petya,” is a ransomware worm that has so far targeted, among others, Ukrainian banks and airports; Russian state-owned oil giant Rosneft; British advertising company WPP, US pharmaceutical giant Merck; and shipping company A.P. Moller-Maersk, which said every branch of its business was affected.

Analysts at several cybersecurity firms have confirmed that the Petya assault utilized a powerful and dangerous cyberweapon reated by the National Security Agency that was leaked in April by the hacker group Shadow Brokers.

Though it’s too soon to be certain, experts say it seems as though a confluence of factors may be pointing to Russian state involvement in carrying out the attack.

‘Ukraine was targeted’

Ukraine was hardest hit by the attack, which came one day before the country’s Constitution Day.

Russia and Ukraine’s rocky relationship has been well-documented, and it has seen a steep decline since Russia annexed the territory of Crimea in 2014 and steadily pursued greater military aggression towards its neighbor.

Read the whole story from Business Insider.

Featured image courtesy of USAF