After years of reading about Tank and months of planning a visit to him in a Colorado prison, I hear the door click open before I see him walk into the room.
I stand up ready to give this former cyber-crime kingpin a professional hello. But, like a cheeky cartoon character, he pokes his head around a pillar with a giant grin on his face and winks.
Tank, whose real name is Vyacheslav Penchukov, climbed to the top of the cyber-underworld not so much with technical wizardry, but with criminal charm.
I am a friendly guy, I make friends easily, the 39-year-old Ukrainian says, with a broad smile.
Having friends in high places is said to be one of the reasons Penchukov managed to evade police for so long. He spent nearly 10 years on the FBI's Most Wanted list and was a leader of two separate gangs in two distinct periods of cyber-crime history.
It is rare to speak to such a high-level cyber-criminal who has left so many victims behind him; Penchukov spoke to us for six hours over two days as part of the ongoing podcast series Cyber Hack: Evil Corp.
The exclusive interview - Penchukov's first ever - reveals the inner workings of these prolific cyber-gangs, the mindset of some of the individuals behind them and never-before-known details about hackers still at large - including the alleged leader of the sanctioned Russian group, Evil Corp.
It took more than 15 years for authorities to finally arrest Penchukov in a dramatic operation in Switzerland in 2022.
There were snipers on the roof and the police put me on the ground and handcuffed me and put a bag on my head on the street in front of my kids. They were scared, he recalls with annoyance.
He is still bitter about how he was arrested, arguing that it was over the top. His thousands of victims around the world would strongly disagree with him: Penchukov and the gangs he either led or was a part of stole tens of millions of pounds from them.
In the late 2000s, he and the infamous Jabber Zeus crew used revolutionary cyber-crime tech to steal directly from the bank accounts of small businesses, local authorities and even charities. Victims saw their savings wiped out and balance sheets upended. In the UK alone, there were more than 600 victims, who lost more than £4m ($5.2m) in just three months.
Between 2018 and 2022, Penchukov set his sights higher, joining the thriving ransomware ecosystem with gangs that targeted international corporations and even a hospital.
Englewood Correctional Facility, where Penchukov is being held, would not let us take any recording equipment inside the prison, so a producer and I make notes during the interview as we are watched over by a guard nearby.
The first thing that stands out about Penchukov is that, although he is eager to be released, he seems in high spirits and is clearly making the most of his time in prison. He tells me he plays a lot of sport, is learning French and English - a well-thumbed Russian-English dictionary stays by his side throughout our interview - and is racking up high-school diplomas. He must be smart, I suggest. Not smart enough - I'm in prison, he jokes.
Englewood is a low-security prison with good facilities. The low-rise but sprawling building sits in the foothills of the Rocky Mountains in Colorado. The dusty grass verges surrounding the prison are teeming with noisy prairie dogs scurrying into their burrows whenever disturbed by prison vehicles coming and going.
It is a long way from Donetsk, Ukraine, where he ran his first cyber-crime gang after falling into hacking through games cheat forums, where he would look for cheats for his favourite video games like Fifa 99 and Counterstrike.
He became the leader of the prolific Jabber Zeus crew - so named because of their use of the revolutionary Zeus malware and their favourite communication platform, Jabber.
Penchukov worked with a small group of hackers that included Maksim Yakubets - a Russian who would go on to be sanctioned by the US government, accused of leading the infamous cyber-group Evil Corp.
Penchukov says that throughout the late 2000s, the Jabber Zeus crew would work out of an office in the centre of Donetsk, putting in six to seven-hour days stealing money from victims overseas. Penchukov would often end his day with a DJ set in the city, playing under the name DJ Slava Rich.
Cyber-crime in those days was easy money, he says. The banks had no idea how to stop it and police in the US, Ukraine and the UK could not keep up.
