mydoom.exe

What is mydoom.exe?

mydoom.exe is the executable component of the Mydoom worm, a historic Windows malware that spreads via email attachments and shared folders. Once on a system, it can create persistence, modify settings, and launch additional payloads to further compromise the device.

The worm uses a multi-stage infection workflow: it drops a copy into system folders, sets startup entries to survive reboots, and attempts to disseminate through contact lists or network shares, sometimes retrieving updates from remote servers.

Types of Mydoom Processes

• Infection Dropper: Initial payload that copies itself to a Windows folder and registers to run on startup.
• Email Spreader: Component responsible for sending the worm to contacts from the compromised host.
• Network Propagator: Attempts to copy itself to accessible network shares and devices.
• Backdoor/Command & Control: Opens a channel for remote commands and status reporting.
• Downloader/Updater: Downloads additional malicious modules or updates from remote servers.
• Persistence Mechanism: Modifies startup entries and registry keys to survive reboots.

Is mydoom.exe Safe?

No, mydoom.exe is malware. It is not a legitimate Windows component and should be treated as a threat.

Is mydoom.exe a Virus or Malware?

The file is malware by design. If found, treat it as a worm that can propagate and backdoor systems.

How to Tell if mydoom.exe is Legitimate or Malware

1. File Location: Check for suspicious paths such as C:\Windows\System32\drivers\mydoom.exe or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\mydoom.lnk. Legitimate system files are not named after the malware.
2. Digital Signature: Right-click the file in Explorer -> Properties -> Digital Signatures. Should not show a valid Microsoft signature; malware typically lacks one.
3. Resource Usage: Unusual spikes in network activity or CPU usage when idle indicate malicious behavior.
4. Behavior: If the process emails itself, copies to network shares, or creates new startup entries, it is malicious.

Why Is mydoom.exe Running on My PC?

Mydoom.exe runs to propagate, maintain persistence, and perform its malicious tasks. It may launch on startup, during user activity, or when network conditions trigger secondary payloads.

Reasons it's running:

• Active Infection: The worm is executing its core propagation and payload routines while the system remains compromised.
• Startup Persistence: Registry Run keys or startup folders cause the worm to relaunch after reboots.
• Background Mail Propagation: Email-sending components attempt to spread to contacts or downstream recipients.
• Network Propagation: Attempts to move via shared folders or nearby devices, increasing infection surface.
• Command & Control Contact: The worm may reach out to remote servers for commands or updates.

Can I Disable or Remove mydoom.exe?

Yes, you can remove mydoom.exe. Stop the process, remove its startup entries, and perform a full malware cleanup with an updated antivirus.

How to Stop mydoom.exe

• End Active Processes: Open Task Manager, locate mydoom.exe and related processes, and End Task.
• Disconnect from Network: If possible, disconnect from the network to stop propagation and C2 communication.
• Disable Startup: Task Manager > Startup tab > Disable any Mydoom-related entries.
• Remove Scheduling: Check and delete startup tasks or registry Run entries that launch mydoom on boot.
• Run a Clean Antivirus Scan: Update signatures and perform a full system scan; quarantine or delete detected components.

How to Remove Mydoom

• ✔ Boot into Safe Mode with Networking
• ✔ Update and run a full system antivirus/anti-malware scan
• ✔ Remove any detected Mydoom files from paths like C:\Windows\System32\drivers\mydoom.exe and C:\Users\Public\Documents\mydoom_update.exe
• ✔ Clean up startup entries and scheduled tasks referencing Mydoom
• ✔ Reset affected network settings and monitor for reinfection

Common Problems: Malware Persistence and Spread

Infections with mydoom.exe can cause persistent startup, network-related abuse, and unexplained system slowdowns. Here are typical problems and fixes.

Common Causes & Solutions

• Infection via email attachments: Do not open unexpected attachments; run a full malware scan and remove the infection.
• Startup persistence: Remove Run keys and startup shortcuts, then reboot and scan again.
• Network propagation: Isolate the machine, block outbound SMTP and SMB if possible, and scan all hosts on the network.
• Disabled security software: Reinstall or repair antivirus, apply the latest definitions, and perform a deep scan.
• Modified hosts or firewall rules: Restore hosts file and firewall settings to default; monitor for new rules.
• Outdated OS/patches: Update Windows with the latest security patches and enable automatic updates.

Related Processes