How to Detect and Block Password Protected File Threats using Go

Cloudmersive
2 min readJun 15, 2023

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Password protected files are frequently used to bypass weakly configured file security policies and eventually inject malware payloads. It’s often best to block these files from a sensitive upload process altogether, and you can accomplish that easily using the free API provided below. This API scans files for millions of virus and malware signatures, and it automatically detects a variety of hidden threat types, including password protected files. You can block password protected files by setting the (“allowPasswordProtectedFiles”, “<boolean>”) request parameter to “false”.

To take advantage of this API for free, you’ll need a free-tier API key, which can be obtained by creating a free account on the Cloudmersive website. After that, you can easily structure your API call using ready-to-run code examples in Go:

package main

import (
"fmt"
"bytes"
"mime/multipart"
"os"
"path/filepath"
"io"
"net/http"
"io/ioutil"
)

func main() {

url := "https://api.cloudmersive.com/virus/scan/file/advanced"
method := "POST"

payload := &bytes.Buffer{}
writer := multipart.NewWriter(payload)
file, errFile1 := os.Open("/path/to/file")
defer file.Close()
part1,
errFile1 := writer.CreateFormFile("inputFile",filepath.Base("/path/to/file"))
_, errFile1 = io.Copy(part1, file)
if errFile1 != nil {
fmt.Println(errFile1)
return
}
err := writer.Close()
if err != nil {
fmt.Println(err)
return
}


client := &http.Client {
}
req, err := http.NewRequest(method, url, payload)

if err != nil {
fmt.Println(err)
return
}
req.Header.Add("allowExecutables", "<boolean>")
req.Header.Add("allowInvalidFiles", "<boolean>")
req.Header.Add("allowScripts", "<boolean>")
req.Header.Add("allowPasswordProtectedFiles", "<boolean>")
req.Header.Add("allowMacros", "<boolean>")
req.Header.Add("allowXmlExternalEntities", "<boolean>")
req.Header.Add("allowInsecureDeserialization", "<boolean>")
req.Header.Add("allowHtml", "<boolean>")
req.Header.Add("restrictFileTypes", "<string>")
req.Header.Add("Content-Type", "multipart/form-data")
req.Header.Add("Apikey", "YOUR-API-KEY-HERE")

req.Header.Set("Content-Type", writer.FormDataContentType())
res, err := client.Do(req)
if err != nil {
fmt.Println(err)
return
}
defer res.Body.Close()

body, err := ioutil.ReadAll(res.Body)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(string(body))
}

All files containing viruses & malware or violating custom content threat detection policies will receive a “CleanResult: False” response, making it easy to remove these files from your upload process.

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Cloudmersive
Cloudmersive

Written by Cloudmersive

There’s an API for that. Cloudmersive is a leader in Highly Scalable Cloud APIs.

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