It’s a problem which grew to monstrous proportions in the past 25 years of post-Soviet rule.
When pro-democracy activists entered the home of Viktor Pshonka, the former regime’s prosecutor general, last February, they found: gold-plated bathroom ware; gem-encrusted clocks; a marble swimming pool; and oil paintings of himself as a Roman Emperor and as Napoleon.
He got his money in various ways.
Pshonka’s office, an army of 18,000 bureaucrats, seized control of whole sectors of Ukraine’s economy, such as the real estate sector, by extorting people via investigations and by dictating court verdicts against their victims.
Pshonka fled to Russia with the former president, Viktor Yanukovych, after the revolution.
But the new prosecution chiefs, first, Vitaly Yarema, now, Viktor Shokin, still preside over a system which looks more like a crime syndicate than a law enforcement agency.
Ukrainian media have published images of Yarema’s 10,000 square metre estate, the value of which is silly compared to his official salary.
He appointed ex-Yanukovych stooges to big posts and sent letters to Brussels to try to get them off blacklists.
Shokin also caused scandals by trying to quash anti-corruption probes into his clan.
“Corporate raiding is still very frequent. For instance, if a large Ukrainian firm wants to buy a competitor’s assets, they may still, often, contact their friends in the prosecutor’s office … and get them to initiate a case against their target”, Kalman Mizsei, the head of the EU’s rule of law mission in Kiev, Euam Ukraine, told EUobserver.
“There’s still no concept of public service. There’s widespread buying and selling of positions”, he added.
“There’s [also] an open fight between reformers and recidivists … it goes to the point that criminal investigations are being opened against some of the reformers”, he said.
“The prosecution is the backbone of the old system. It’s vital to clean it up, to reduce its power, and to make it respectable”.
Mizsei's task is daunting, to say the least.
His operation, Euam Ukraine, created in July, has 160 people, most of them police and judicial experts from Germany, Romania, Sweden, and the UK.
By contrast, Eulex, the EU rule of law of mission in Kosovo, which has a population 25 times smaller than Ukraine, has 1,500 people.
It also has an executive mandate, which means Eulex can indict corrupt Kosovo officials.
But Euam Ukraine can only give advice.
The Shokin machine is part of a bigger, and equally ugly, picture.
Ukrainian leader Petro Poroshenko has stepped in to get bent prosecutors sacked.
But the president, himself an oligarch who never sold off his business interests, isn’t keen to let go the power to appoint prosecutor generals.
He answers to parliament, but, by some estimates, three-quarters of MPs still have an old-school, Yanukovych-type mentality.
The MPs answer to Ukrainian people.
But despite the revolution, 25 years of misrule have left a legacy of what Mizsei called “deep nihilism” in Ukrainian society.
Meanwhile, the EU reform effort comes at time of war.
Russia’s assault is both military and political:
Reports of Ukraine corruption are grist to the Kremlin propaganda mill.
The worst case scenario is loss of EU, International Monetary Fund, and foreign investor confidence, aggravating Ukraine’s economic crisis.
It’s also loss of faith by the "Maidan" revolution and east Ukraine war veterans, prompting political instability or civil unrest.
It amounts to a failing state, left alone by the West to become, once again, Russia’s client.
The ugly picture is not uniform, however.
Poroshenko has shown interest in reform and has the majority in parliament to see it through.
Mizsei said Ukraine’s new traffic police has won public trust.
He said its security service, the SBU, has been purged of Russian infiltrators and has distinguished itself by “uncovering and preventing terrorist attacks [by Russia's irregular forces]”.
He said the prosecution service also contains a new, highly-motivated cadre, which is trying to change it from within - not least the new deputy prosecutor general, Davit Sakvarelidze, a Georgian national.
Despite the “nihilism”, the EU diplomat also noted that Ukrainian civil society is making a big difference.
He spoke highly of two NGOs - Reanimation Package of Reforms and the Renaissance Foundation, a branch of the Open Society Foundations, a US-based body - for keeping a “close watch” on Poroshenko’s promises.
“Roman Romanov, from Renaissance, and others, have made an impact by initiating pragmatic projects”, Mizsei told this website.
He said one of Romanov’s initiatives, the creation of pro bono legal aid centres for defendants, is keeping prosecutors in check.
Georgian model Poroshenko has also appointed Georgia’s former president, Mikheil Saakashvili, as governor of Odessa, a city in south Ukraine.
It’s a red rag to Russian leader Vladimir Putin, who went to war against Saakashvili in 2008.
But the Georgian element in Ukraine is part of the anti-corruption shift.
Mizsei noted that Saakashvili, in his eight years in power, “showed that a radical approach to wiping out corruption is possible in the post-Soviet sphere”.
The EU diplomat said, if things go well, Ukraine could, in the next “four or five years” also become “a medium-level rule of law country”.
“But for this, reforms need to intensify”.