In one campaign, according to a report published by researchers from security firm FireEye, attackers are spreading files that purport to contain stolen data. One file, titled leaks copy.rar, contains email addresses and passwords that were supposedly compromised in a breach. Attackers claim another file, cc.rar, contains stolen credit card data. Other files have names including zabugor.rar, ZabugorV.rar, Combolist.rar, Nulled2019.rar, and IT.rar.

Hidden inside the files are payloads from a variety of different malware families. They include a keylogger known as QuasarRat and malware containing Chinese language text known as Buzy.

The FireEye report identified three other campaigns, including:

• One that impersonates an educational accreditation body that seems to use a PDF letter copied from the website of the Council on Social Work Education as a decoy. When extracted, the RAR file plants a Visual Basic script in the computer's startup folder. The script causes the computer to install a remote-access trojan called Netwire.

• An attack targeting the Israeli military industry that uses decoy files related to SysAid, a helpdesk service based in Israel. A malicious payload, dubbed SappyCache, will decrypt a file stored in a temporary folder to obtain the address of a command and control channel. SappyCache will then attempt to download and install a second-stage malware file from the server. The server never responded during the FireEye analysis.

• An attack potentially targeting a single person in Ukraine that uses a purported PDF message from the country's former President Viktor Yanukovych. The exploit drops a batch file into the startup folder that, when executed, installed a payload dubbed Empire.

FireEye isn't the only firm that's seeing such exploits. A separate report from security firm Symantec said that an espionage hacking outfit known both as Elfin and APT33 has been spotted exploiting the WinRAR vulnerability against a target in the chemical industry of Saudi Arabia.

Attackers sent a spear-phishing email to at least two employees in the targeted company. The email included a file dubbed JobDetails.rar. If extracted on a computer using a vulnerable version of WinRAR, the attack could install any file of the attackers' choice. Prior to the attack, Symantec updated its software to block exploits. The protection prevented the attack from working against the targeted company.