Menace actors have revealed yet one more spherical of malicious packages to Python Bundle Index (PyPI) with the purpose of delivering information-stealing malware on compromised developer machines.
Apparently, whereas the malware goes by a wide range of names like ANGEL Stealer, Celestial Stealer, Fade Stealer, Leaf $tealer, PURE Stealer, Devil Stealer, and @skid Stealer, cybersecurity firm Phylum discovered all of them to be copies of W4SP Stealer.
W4SP Stealer primarily capabilities to siphon consumer knowledge, together with credentials, cryptocurrency wallets, Discord tokens, and different information of curiosity. It is created and revealed by an actor who goes by the aliases BillyV3, BillyTheGoat, and billythegoat356.
“For some motive, every deployment seems to have merely tried to do a discover/exchange of the W4SP references in alternate for another seemingly arbitrary identify,” the researchers stated in a report revealed earlier this week.

The 16 rogue modules are as follows: modulesecurity, informmodule, chazz, randomtime, proxygeneratorbil, easycordey, easycordeyy, tomproxies, sys-ej, py4sync, infosys, sysuptoer, nowsys, upamonkws, captchaboy, and proxybooster.
The marketing campaign distributing W4SP Stealer gained traction round October 2022, though indications are that it might have began way back to August 25, 2022. Since then dozens of extra bogus packages containing W4SP Stealer have been revealed on PyPI by the persistent menace actors.
The newest iteration of the exercise, for what it is value, makes no apparent to cover its nefarious intentions, besides within the case of chazz, which leverages the package deal to obtain obfuscated Leaf $tealer malware hosted on the klgrth[.]io paste service.
It is value noting that earlier variations of the assault chains have additionally been noticed fetching next-stage Python code straight from a public GitHub repository that then drops the credential stealer.
The surge in new copycat variants dovetails with GitHub’s takedown of the repository that held the unique W4SP Stealer supply code, indicating that cybercriminals doubtless not affiliated with the operation are additionally weaponizing the malware to assault PyPI customers.
“Open-source ecosystems resembling PyPI, NPM, and the like are enormous simple targets for these sorts of actors to attempt to deploy this type of malware on,” the researchers stated. Their makes an attempt will solely develop into extra frequent, extra persistent, and most refined.”
The software program provide chain safety agency, which saved tabs on the menace actor’s Discord channel, additional famous {that a} beforehand flagged package deal below the identify of pystyle was trojanized by BillyTheGoat to distribute the stealer.
The module has not solely racked by hundreds of downloads every month, but in addition began off as an innocuous utility in September 2021 to assist customers type console output. The malicious modifications had been launched in variations 2.1 and a pair of.2 launched on October 28, 2022.
These two variations, which had been reside on PyPI for about an hour earlier than they had been pulled, are alleged to have gotten 400 downloads, BillyTheGoat informed Phylum in an “unsolicited correspondence.”
“Simply because a package deal is benign at this time and has proven a historical past of being benign for years doesn’t imply it is going to stay this fashion,” the researchers cautioned. “Menace actors have proven great persistence in constructing professional packages, solely to poison them with malware after they’ve develop into sufficiently in style.”