Microsoft recently announced that a number of cloud services, including OneDrive and SharePoint, will scan Zip files that users upload or share and set password protection.
Microsoft said that cyber criminals have long used archived documents to distribute malware. Microsoft’s cloud services have previously been limited to scanning zip files that are not password-protected, which malware distributors can set to bypass antivirus engines.
Andrew Brandt, a security researcher, said Monday that Microsoft has begun scanning for password-protected Zip archives on SharePoint.
He purposely compressed several malware samples into encrypted Zip files, which will flag the presence of malware in the files after they are uploaded to Microsoft Cloud Services.
For users who don’t want Microsoft to scan encrypted files, try using a different compression format such as 7-Zip, or use an AES-256 encryption algorithm, for example.
