But their claims have been called into question by Emsisoft's ransomware threat researcher Brett Callow who has described the group as a "bunch of lowlifes", adding that lowlifes are not known for their honesty.
He said his reasoning was based on several factors that had been noticed in the behaviour of groups using Maze after the pandemic began: a change from listing two or three firms in a day to listing a much larger number; posting password-protected archives for which the passwords did not work; auctioning data after the COVID-19 crisis got into full swing; and another group, REvil, claiming to have data on Donald Trump and then claiming to have sold it.
Callow added that it now looked like these groups could be auctioning data from old attacks that happened before they launched their leak site, all tactics that seemed to indicate desperation.
Another screenshot showed an archive file with a .KDZ extension, the format for official stock firmware code from LG, the website Bleeping Computer reported.
Judging by the filenames, the files appear to refer to firmware for AT&T devices that were developed for the US market. There are a 41 LG devices listed on the AT&T website.
And a third screenshot listing source for an email forwarding script indicates the owner is from the lgepartner.com domain which is owned by LG Electronics.
The group had hinted about the LG hack a few days back, saying in one of its so-called "press releases": "And some future presentation. Soon you’ll be able to know how the LG company have lost the source code of its products for one very big telecommunications company, working worldwide."
On its South Korean website, LG only has a general email form for submitting queries relating to its products. iTWire emailed the company's US office for comment but the email bounced, saying there was no such user.
Given that, iTWire has written to five individuals listed on the media contacts page, all of whom are for the US only, seeking comment.
An LG spokesman responded to iTWire's request, saying: "At LG, we take cyber security issues very seriously. We are looking into this alleged incident and will involve appropriate law enforcement agencies if there is evidence that a crime has been committed. To date, we have not received communication from any party taking responsibility for this supposed theft."
Said Callow: "The Maze group are criminal lowlifes, and criminal lowlifes are not noted for their honesty. Consequently, their claims should be taken with a pinch — no, make that a bucketful — of salt.
"Whether they actually have the data the claim to have in every case is very questionable. In some cases, it would certainly appear that they did not and were simply attempting to shake companies down by exaggerating — or outright lying — about the amount of data they had obtained in an attack, if there even was an attack."