Replication Through Removable Media

Created the Friday 18 October 2024. Updated 3 hours ago.

Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes.

Technique Identifiers

U1012 T1091

Code Snippets

import pyudev, time, os


def getMountPath(devPath):
    #print(f'[+] Grabbing mount path for {devPath}')
    time.sleep(20) # We sleep for a bit to give the /proc/mounts file time to refresh & contain mount path for devpath
    try:
        with open("/proc/mounts", "r") as mFile:
            #print('[+] Reading /proc/mounts')
            for line in mFile:
                parts = line.split()
                if devPath.strip() in parts:
                        #print(f'[+] Mount path found for {devPath}: {parts[1]}') #parts[1] -> full file path
                        return parts[1]
    except:
        print("[!] Cannot open /proc/mounts!")
        
def getDevPath():
    print('[-] Waiting for USB device insertion...')
    context = pyudev.Context()

    monitor = pyudev.Monitor.from_netlink(context)
    monitor.filter_by('block')

    monitor.start()

    for device in iter(monitor.poll, None):
        if device.device_type in ('disk', 'partition'):
            device_node = device.device_node
            if device.action == 'add':
                print(f'[+] Device connected: {device_node}!')
                

                mntPath = getMountPath(device_node)
                if mntPath is not None:
                	print(f'[+] Mount path for {device_node}: {mntPath}')

def main():
	getDevPath()

if __name__ == '__main__':
	main()

Contributors

Issac Briones (1d8)

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

Replication Through Removable Media, Technique T1091 - Enterprise | MITRE ATT&CK®