Secure Soft P7S Viewer - The digitally signed files using P7S or P7M format has the mime-type application/pkcs7-signed-data type. Details about the standard regarding the creation of such structures are published on RFC 3369, standard initiated by RSA Security Data Inc. P7S Viewer lets you view files signed by P7S Signer or other signature software.
P7S Viewer Requirements
– Microsoft .NET Framework 4.6.2 or higher
– Windows 8 or later (including Windows 11 and Windows Server 2022)
Download: 
Secure.Soft.P7S.Viewer.10.1.rar - 2.1 MB