A researcher has uncovered one of many extra uncommon finds within the annals of malware: booby-trapped recordsdata that rat out downloaders and attempt to forestall unauthorized downloading sooner or later. The recordsdata can be found on websites frequented by software program pirates.
Vigilante, as SophosLabs Principal Researcher Andrew Brandt is asking the malware, will get put in when victims obtain and execute what they assume is pirated software program or video games. Behind the scenes, the malware reviews the file title that was executed to an attacker-controlled server, together with the IP tackle of the victims’ computer systems. As a final touch, Vigilante tries to switch the victims’ computer systems to allow them to now not entry thepiratebay.com and as many as 1,000 different pirate websites.
Not your typical malware
“It’s actually uncommon to see one thing like this as a result of there’s usually only one motive behind most malware: stealing stuff,” Brandt wrote on Twitter. “Whether or not that’s passwords, or keystrokes, or cookies, or mental property, or entry, and even CPU cycles to mine cryptocurrency, theft is the motive. However not on this case. These samples actually solely did just a few issues, none of which match the everyday motive for malware criminals.”
However not on this case. These samples actually solely did just a few issues, none of which match the everyday motive for malware criminals.
For one factor, they modify the HOSTS file on the PC so as to add entries. Lots of entries.
They’d a typical theme. pic.twitter.com/O1Z2fSXZ1n
— Accountability Brandt (@threatresearch) June 17, 2021
As soon as victims have executed the trojanized file, the file title and IP tackle are despatched within the type of an HTTP GET request to the attacker-controlled 1flchier[.]com, which may simply be confused with the cloud-storage supplier 1fichier (the previous is spelled with an L because the third character within the title as an alternative of an I). The malware within the recordsdata is essentially similar apart from the file names it generates within the net requests.
Vigilante goes on to replace a file on the contaminated laptop that forestalls it from connecting to The Pirate Bay and different Web locations recognized for use by folks buying and selling pirated software program. Particularly, the malware updates Hosts, a file that pairs a number of area addresses to distinct IP addresses. Because the picture under reveals, the malware pairs thepiratebay.com to 127.0.0.1, a special-purpose IP tackle, usually referred to as the localhost or loopback tackle, that computer systems use to determine their actual IP tackle to different methods.
By mapping the domains to the native host, the malware ensures that the pc can now not entry the websites. The one option to reverse the blocking is to edit the Hosts file to take away the entries.
Brandt discovered a few of the trojans lurking in software program packages out there on a Discord-hosted chat service. He discovered others masquerading as standard video games, productiveness instruments, and safety merchandise out there by BitTorrent.
There are different oddities. Lots of the trojanized executables are digitally signed utilizing a faux code signing instrument. The signatures include a string of randomly generated 18-character uppercase and lowercase letters. The certificates validity started on the day the recordsdata turned out there and is about to run out in 2039. Moreover, the properties sheets of the executables don’t align with the file title.
When considered by a hex editor, the executables additionally include a racial epithet that’s repeated greater than 1,000 instances adopted by a big, randomly sized block of alphabetical characters.
“Padding out the archive with purposeless recordsdata of random size could merely be achieved to switch the archive’s hash worth,” Brandt wrote. “Padding it out with racist slurs informed me all I wanted to find out about its creator.”
Vigilante has no persistence technique, that means it has no option to stay put in. Which means individuals who have been contaminated want solely to edit their Hosts file to be disinfected. SophosLabs offers indicators of compromise right here.