The attacks, first detected and described by WordPress security firm WordFence, targeted WordPress sites across the globe, but most of the malicious traffic originated from a limited set of IP addresses, assigned to an ISP in the Ukraine.
WordFence said that it detected over 1.65 million daily brute-force attempts from a small-time ISP identified only as "Pp Sks-lugan," of which, over 1.5 million came from eight IP addresses, most likely under the control of one single person.
A few days later after WordFence made public their discovery, the company says that Ukrainian users have reached out and provided more information about the "naughty" ISP.
A user by the name of Victor P. has tracked down the infringing ISP to a company named SKS-Lugan that existed for many years in the city of Alchevs'k.
According to a local business guide, the company's CEO is a man named Lizenko Dmitro Igorovich, and SKS-Lugan has around 16 employees.
At the time of writing, Ukrainian authorities have no power over SKS-Lugan because the city of Alchevs'k is in an area controlled by pro-Russian forces in eastern Ukraine.
The city of Alchevs'k is right in the middle of the gray area created by the Ukrainian civil war.
While Victor P. said the ISP is controlled "by Russia," his remarks have no real evidence to suggest this is happening.
A more likely explanation is that the ISP's owner(s), or whoever might be in charge at this time, has agreed to collaborate with cyber-crime syndicates and host servers that carry out malicious operations.
In fact, the IP block assigned to the SKS-Lugan ISP has been involved in a large number of cyber-crime activities.
Currently, the ISP's IP block list is featured in SBL (Spamhaus Block List), a large list that holds up-to-date information on IP addresses from where spam and other criminal activity originates.
The reasons why the IP block is listed is for "spammer & cybercriminal hosting (escalation)" and "ignoring reports, keeping spammers hosted for the money."
According to the SBL page, some of these malicious operations have taken place even before the start of the Ukrainian war. It appears that the recently-discovered wave of brute-force attacks only shined a light on a long-lasting operation.
According to the SBL, this is a small list of cyber-criminal activities hosted on the ISP's IP block:
While Russian President Vladimir Putin has acknowledged that Russian troops were on the ground in the Ukrainian war, it's very unlikely that they've hijacked ISPs so they could brute-force WordPress sites.
Taking into account the ISP's long history with cyber-criminal activities, it appears SKS-Lugan might be one of those bulletproof hosting companies that provide shelter for cyber-criminal operations.
The chaos created by the Ukrainian war most likely helped the ISP by thrusting it into the middle of a geographical zone where international law enforcement pacts don't matter, and police forces can't reach them.
There are no clues that the ISP might be tied to the recent Avalanche malware distribution network takedown by Europol and law enforcement agencies in various countries.
The Avalanche network had been created and coordinated by a Ukrainian man from the city of Poltava, Ukraine. Because authorities didn't follow a proper legal procedure, a judge had to set the suspect free, who used this opportunity and fled.