The company pointed out in its report for the third quarter, which was released on Wednesday, that the supply of already compromised RDP credentials was so great that the price one needed to pay for them was actually falling.
"This is a very worrisome sign as it signals that supply is outstripping demand," Coveware said.
"A larger supply of RDP credentials is the feedstock that draws down the barriers to entry for progressively less technically sophisticated cyber criminals to begin distributing ransomware.
Coveware also found that the average ransom payment had gone up by 31% from the second quarter to US$233,817 (A$325,899). The median payment had risen 2% to US$110,532.
This had happened as ransomware groups had switched to attacking bigger companies "when attackers discovered that the same tactics, techniques, and procedures that work on a 500-person company can work on a 50,000-person company and the potential payoff is substantially higher".
It said the biggest change over the past six quarters was that attackers had realised that their tactics would scale well, without any big increase in their operating costs.
"This problem will continue to get worse until pressure is applied to the unit economics of this illicit industry," it said.
"It is also possible that the influx of remote and work-from-home set-ups using RDP and other remote technologies allowed threat actors to leverage attack vectors that previously didn’t exist."
Half of the ransomware cases documented by Coveware used data exfiltration as a pressure tactic. But it was unwise to assume that yielding to a ransom demand meant that the attackers would keep to their word and delete the exfiltrated data.
The firm cited the cases of five ransomware groups which did not keep to their word on deleting data:
- Sodinokibi/REvil: Victims that paid were re-extorted weeks later with threats to post the same dataset.
- Maze / Sekhmet / Egregor (related groups): Data posted on a leak site accidentally or wilfully before the client understood there was data taken.
- NetWalker: Data posted of companies that had paid for it not to be leaked.
- Pysa/Mespinoza: Data posted of companies that had paid for it not to be leaked.
- Conti: Fake files were shown as proof of deletion.
Coveware said its policy was to advise victims that:
- "The data will not be credibly deleted. Victims should assume it will be traded to other threat actors, sold, or held for a second/future extortion attempt;
- "Custody of stolen data was held by multiple parties and not secured. Even if the threat actor deletes a volume of data following a payment, other parties that had access to it may have made copies so that they can extort the victim in the future; and
- "The data may get posted anyway by mistake or on purpose before a victim can even respond to an extortion attempt."
The study observed that different groups took different intervals of time to post their victims' data on a leak site. Maze, a group that has just shut down, took about six months to post the data of 50 victims.
DoppelPaymer and REvil/Sodinokibi took about the same time.
But NetWalker took only three months, while Conti (six weeks) and Egregor (three weeks) took even less time to dox 50 victims.
The full report can be seen here.