North Korean hackers responsible for Contagious Interview are trapping job seekers in the cryptocurrency sector by using the popular ClickFix social-engineering attack strategy. They aimed to deploy a Go-based backdoor— earlier undocumented— known as GolangGhost on Windows and macOS systems.
Hackers lure job seekers
The latest attack, potentially a part of a larger campaign, goes by the codename ClickFake Interview, according to French cybersecurity company Sekoia. Aka DeceptiveDeployment, DEV#POPPER, and Famoys Chollima; Contagious Interview has been active since December 2022, however, it was publicly reported only after late 2023.
The attack uses legitimate job interview sites to promote the ClickFix tactic and deploy Windows and MacOS backdoors, said Sekoia experts Amaury G., Coline Chavane, and Felix Aimé, attributing the attack to the notorious Lazarus Group.
Lazarus involved
One major highlight of the campaign is that it mainly attacks centralized finance businesses by mimicking firms like Kraken, Circle BlockFi, Coinbase, KuCoin, Robinhood, Tether, and Bybit. Traditionally, Lazarus targeted decentralized finance (DeFi) entities.
Attack tactic explained
Like Operation Dream Job, Contagious Interview also uses fake job offers as traps to lure potential victims and trick them into downloading malware to steal sensitive data and cryptocurrency. The victims are approached via LinkedIn or X to schedule a video interview and asked to download malware-laced video conference software that triggers the infection process.
Finding of Lazarus ClickFix attack
Security expert Tayloar Monahan first reported the Lazarus Group’s use of ClickFix in late 2022, saying the attack chains led to the installment of a malware strain called FERRET that delivered the Golang backdoor. In this malware campaign, the victims are prompted to use a video interview, ‘Willow,’ and do a sell video assessment.
The whole process is carefully built to gain users and “proceeds smoothly until the user is asked to enable their camera,” Sekoia said. At this stage, an “error message appears, indicating that the user needs to download a driver to fix the issue. This is where the operator employs the ClickFix technique," adds Sekoia.
Different attack tactics for Windows and MacOS users
The prompts given to victims may vary depending on the OS. For Windows, victims are asked to open the Command Prompt and run a curl command to perform a Visual Basic Script (VBS) file to launch a basic script to run GolanGhost. MacOS victims are prompted to open the Terminal app and perform a curl command to run a malicious shell script, which then runs another shell script that runs a stealer module called FROSTYFERRET—aka ChromwUpdateAlert— and the backdoor.
