Greg Myre

CIA Director William Burns says he has redoubled the agency's efforts to uncover the cause of Havana syndrome — the mysterious set of ailments that has afflicted more than 200 U.S. officials and family members around the world.

Just days after the Sept. 11 attacks, a handful of CIA officers were the first Americans sent into Afghanistan. Gary Schroen was one of them, and he recalled his marching orders.

The recent ransomware attacks on the U.S. gas and meat industries have sparked renewed conversations about the possibility of an international cyber agreement that would set the ground rules for what is and isn't permissible, and spell out sanctions for violators.

If you want to extort millions of dollars from a large U.S. company, you can't do it alone. It takes a village. A village of hackers with advanced computer skills, who hang out on the Dark Web, and most likely live in Russia.

"Ransomware has become a huge business, and as in any business, in order to scale it, they're coming up with innovative models." said Dmitri Alperovitch, head of the technology group Silverado Policy Accelerator in Washington.

The problem has long plagued bank robbers and drug smugglers: how to transport and hide huge sums of ill-gotten gains without getting caught?

In the past few years, ransomware hackers have found an almost perfect solution — cryptocurrencies like Bitcoin. It's fast. It's easy. Best of all, it's largely anonymous and hard to trace.

President Biden received no grace period when it came to cyber hacks.

"The cyber pressures that this administration has faced so far have been relentless," said April Falcon Doss, a former National Security Agency official who now heads a technology program at the Georgetown University Law Center.

President Biden and his Pentagon chiefs say the U.S. will assist Afghanistan's military from afar after American troops pull out. They haven't announced the details, but they do have a common refrain: "over the horizon."

"We will maintain an over-the-horizon capacity," Biden said in his recent address to a joint session of Congress.

"We will continue to support (the Afghans) with over-the-horizon logistics," Defense Secretary Lloyd Austin said at a recent new conference.

Exploding cigars. Poisoned pens. Booby-trapped seashells. These were just a few of the outlandish CIA plots to kill former Cuban leader Fidel Castro, who died of natural causes in 2016 at age 90.

Yet new details have emerged of the first such plan, which was actually directed against Castro's brother Raúl Castro, in July 1960, just a year and a half after the Castros had come to power in a revolution.

The NBA's Houston Rockets were hit by a ransomware attack earlier this month. Now it's the Washington, D.C., police department. The common thread is a ransomware group called Babuk, which was unknown and likely didn't exist until it began posting on the dark web early this year.

The U.S. intelligence community said Tuesday that it views four countries as posing the main national security challenges in the coming year: China, followed by Russia, Iran and North Korea.

"China increasingly is a near-peer competitor, challenging the United States in multiple arenas — especially economically, militarily, and technologically — and is pushing to change global norms," said the report released by the Office of the Director of National Intelligence.

The National Security Agency considers itself the world's most formidable cyber power, with an army of computer warriors who constantly scan the wired world. Yet by law, the NSA only collects intelligence abroad, and not inside the U.S.

U.S. rivals like Russia are aware of this blind spot and know how to exploit it, as the NSA director, Army Gen. Paul Nakasone, explained recently to the Senate Armed Services Committee.

At Countryside High School in Clearwater, Fla., 16-year-old Sage Waite is already taking a class in cybersecurity, and she'd welcome one that's in the works on cyber disinformation.

"For the longest time, I didn't actually know what disinformation was," said Waite, who's in the 11th grade. "There was always the idea that things could be wrong in what you're hearing and what you're being told. But the idea of misinformation and disinformation wasn't in my day-to-day."

A new report by the U.S. intelligence community on Tuesday says Russia sought to help former President Donald Trump in last year's presidential election. But the document also emphasized there was no indication Russia or any other country attempted to alter actual votes.

More than 300 suspects from the Jan. 6 riot at the Capitol face a variety of charges — illegal weapons, assault, property damage and conspiracy. In the latest development, two men have been arrested and charged with spraying a chemical at policeman Brian Sicknick, who died the following day.

As the top U.S. intelligence official for just over a month, Avril Haines has an overflowing inbox.

Updated at 7:32 p.m. ET

Saudi Arabia's crown prince approved the operation that led to the brutal 2018 death of journalist Jamal Khashoggi, the U.S. intelligence community said in a report released Friday.

President Biden has been critical of Saudi Arabia and the report is expected to further harm the increasingly fraught relations between the two longtime allies. He said Friday that he will hold Saudi Arabia accountable for human rights abuses.

President Biden's nominee to lead the CIA, William Burns, spent more than three decades as a diplomat. Yet Burns sounded very much like a national security chief at his confirmation hearing Wednesday as he described how the U.S. should be wary of China and its leader Xi Jinping.

"There are a growing number of areas in which Xi's China is a formidable, authoritarian adversary," Burns told the Senate Intelligence Committee in his opening remarks.

As COVID cases began to rise a year ago, a Chinese company contacted several U.S. states and offered to set up testing labs. As a byproduct, the Chinese firm, Beijing Genomics Institute, would likely gain access to the DNA of those tested.

Last year, cyber expert P.W. Singer was asked to write the introduction to a big government report by a group called the Cybersecurity Solarium Commission. Instead of the usual bland summary, Singer produced a fictional account of what Washington, D.C., might look like in the aftermath of a devastating cyberattack.

The riot at the Capitol appeared to be almost all chaos and anarchy. But as private researchers and ordinary individuals scrutinized online video and photos, they identified some of those who took part and assisted law enforcement.

John Scott-Railton from Citizen Lab at the University of Toronto focused on individuals who seemed to have a real purpose amid the mob — like two men who were spotted with plastic handcuffs that could be used to detain people or take them hostage.

In a day filled with shocking images, one of the most startling was a mob of President Trump's supporters surging into the U.S. Capitol with relative ease.

Editor's Note: As this year winds down, we're looking back at some people we spoke to earlier in 2020, when the coronavirus pandemic was in its early stages. Now that there's a vaccine, we wanted to check in with someone whose family has a long history with vaccines.

When I spoke to Dr. Peter Salk back in May, he told me the tale of receiving an early polio vaccine - the one invented by his father, Dr. Jonas Salk.

The first word that hackers had carried out a highly sophisticated intrusion into U.S. computer networks came on Dec. 8, when the cybersecurity firm FireEye announced it had been breached and some of its most valuable tools had been stolen.

A massive computer breach allowed hackers to spend months exploring numerous U.S. government networks and private companies' systems around the world. Industry experts say a country mounted the complex hack — and government officials say Russia is responsible.

The hackers attached their malware to a software update from SolarWinds, a company based in Austin, Texas. Many federal agencies and thousands of companies worldwide use SolarWinds' Orion software to monitor their computer networks.