How to Detect Files Containing Macros in your File Upload Process using Ruby

Malicious macros can unleash devastating cyberattacks once activated. Given the scope of that threat, it’s generally prudent to remove any documents containing macros from an external-facing file upload process. You can accomplish that easily using the below code; this calls a free Virus Scan API that checks files for millions of virus and malware signatures — including ransomware, spyware, and more — and performs in-depth content verification to detect Macros and other content threats present within a document.

You can install the SDK using the below command:

gem 'cloudmersive-virus-scan-api-client', '~> 2.0.3'

And you can structure your API call using the below code (provide a free-tier API key to authenticate up to 800 API calls per month):

# load the gem
require 'cloudmersive-virus-scan-api-client'
# setup authorization
CloudmersiveVirusScanApiClient.configure do |config|
  # Configure API key authorization: Apikey
  config.api_key['Apikey'] = 'YOUR API KEY'
  # Uncomment the following line to set a prefix for the API key, e.g. 'Bearer' (defaults to nil)
  #config.api_key_prefix['Apikey'] = 'Bearer'
end

api_instance = CloudmersiveVirusScanApiClient::ScanApi.new

input_file = File.new('/path/to/inputfile') # File | Input file to perform the operation on.

opts = { 
  allow_executables: true, # BOOLEAN | Set to false to block executable files (program code) from being allowed in the input file.  Default is false (recommended).
  allow_invalid_files: true, # BOOLEAN | Set to false to block invalid files, such as a PDF file that is not really a valid PDF file, or a Word Document that is not a valid Word Document.  Default is false (recommended).
  allow_scripts: true, # BOOLEAN | Set to false to block script files, such as a PHP files, Python scripts, and other malicious content or security threats that can be embedded in the file.  Set to true to allow these file types.  Default is false (recommended).
  allow_password_protected_files: true, # BOOLEAN | Set to false to block password protected and encrypted files, such as encrypted zip and rar files, and other files that seek to circumvent scanning through passwords.  Set to true to allow these file types.  Default is false (recommended).
  allow_macros: true, # BOOLEAN | Set to false to block macros and other threats embedded in document files, such as Word, Excel and PowerPoint embedded Macros, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
  allow_xml_external_entities: true, # BOOLEAN | Set to false to block XML External Entities and other threats embedded in XML files, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
  allow_insecure_deserialization: true, # BOOLEAN | Set to false to block Insecure Deserialization and other threats embedded in JSON and other object serialization files, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
  allow_html: true, # BOOLEAN | Set to false to block HTML input in the top level file; HTML can contain XSS, scripts, local file accesses and other threats.  Set to true to allow these file types.  Default is false (recommended) [for API keys created prior to the release of this feature default is true for backward compatability].
  restrict_file_types: 'restrict_file_types_example' # String | Specify a restricted set of file formats to allow as clean as a comma-separated list of file formats, such as .pdf,.docx,.png would allow only PDF, PNG and Word document files.  All files must pass content verification against this list of file formats, if they do not, then the result will be returned as CleanResult=false.  Set restrictFileTypes parameter to null or empty string to disable; default is disabled.
}

begin
  #Advanced Scan a file for viruses
  result = api_instance.scan_file_advanced(input_file, opts)
  p result
rescue CloudmersiveVirusScanApiClient::ApiError => e
  puts "Exception when calling ScanApi->scan_file_advanced: #{e}"
end

You can set booleans to block Macros and other non-malware content threats as per your needs. It’s just that easy to boost your application’s threat profile!