Umbrella was what spontaneously came to my mind too when I read the title (plus, they have also branded the Pope).
But I think that the Weyland-Yutani conglomerate is a strong contender, too. Autonomous, life-like kill-capable androids sold everywhere, xenomorph research for their bioweapons department (which, it is alluded to, is publicly listed at the stock market and in competition with other bioweapons developers, how crazy is that). Their willingness to sacrifice settlers and, ultimately, humanity on Earth itself, the inability of governments to keep them under control ... ticks all the boxes.
Greedy maybe, like any other corporation, but their business practices brought us also the biggest possible library of software. Without Microsoft licensing DOS (and later WIndows) idenpendently to a multitude of hardware vendors, maybe they quasi-monopolized the market for personal computer operating systems but at the same time they opened up the market for competition which would otherwise have been a fight between IBM and, maybe, Apple. Also, it's not like there were never alternatives to operating systems from Microsoft. DR-DOS, Linux, BSD ... the vast majority of people however decided that MS offered them the best deal. If MS became a towering giant, it is because billions of people made purchasing decisions that rejected the alternatives.
Besides, this being the "Science fiction" board, I think it's fair to say that only corporations of fiction are eligible.
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt. Bertrand Russell, 1872 - 1970. Indeed the safest road to Hell is the gradual one - the gentle slope, soft underfoot, without sudden turnings, without milestones, without signposts. C.S. Lewis, 1898 - 1963. History is made up of people recovering from the last disaster. James S.A. Corey.
They literally just want to see the world burn, and have no other motives besides being evil. They even have their badness spelled in their name, I mean how many other corporations just put Terrorism, Revenge and Extortion in their name?
And then the wikipedia article
Members who fail missions are immediately executed, usually in gory and spectacular ways. In the novel, Blofeld electrocutes one member in his chair for sexually molesting a girl who had been kidnapped by the organization; he had previously strangled a second to death with a garrote and shot a third through the heart with a compressed-air pistol.
- Dr. Julius No (Dr. No) – boiled alive in his own nuclear reactor. - Tov Kronsteen (No. 5, From Russia with Love) – killed on Blofeld's orders by Morzeny with poisoned stabbing shoe - Quist (Thunderball) – thrown by Largo into shark pool - Number 3 (You Only Live Twice) – blown up in volcano explosion
SPECTRE at least was a "for profit organization" with a board of directors (apparently reinvesting all their money into extravagant executive hideouts). And, according to Evil Genius (the underappreciated base-building RTS from around 2000), it's plausible that each terror center also had it's "legitimate business front" with Mr. and Mrs. Henchman type employees not signing up for the terror part. If you left a door open while torturing a pesky government agent, those employees would flee your organization (also, you had to gloat and reveal your plans to said intruders as the only means to gain victory points ... which explains a lot).