Removal instructions for the Cloud 9 JavaScript BotNet malware

What is Cloud 9 JavaScript BotNet?

Cloud 9 JavaScript BotNet refers to a malicious browser extension capable of causing chain infections, which can result in the attackers assuming near-user-level control of the device. This malware is compatible with Google Chrome, Mozilla Firefox, Microsoft Edge, Internet Explorer, and other browsers.

Cloud 9 infections lead to the cyber criminals gaining the ability to access/control victims' devices; essentially, it operates as a RAT (Remote Access Trojan). RATs tend to be very versatile, and Cloud 9 is not an exception. It can add compromised machines into a botnet, launch DDoS attacks, steal data from browsers and systems, install additional malicious content/programs, and mine cryptocurrency.

Cloud 9 is commonly distributed through deceptive Adobe Flash Player update websites, and it can appear as a Flash Player extension on Chrome browsers. This malware has been on the market for a while; its been available on hacker forums since 2017 - therefore, it is likely spread using a wide variety of techniques.

Cloud 9 JavaScript BotNet malware overview

Following successful infiltration, Cloud 9 begins collecting relevant data concerning the system and installed browsers. This data harvesting is important for further stages of the infection, as the malware's goal is to inject malicious code and programs into the device - thus assuming full control over it.

Cloud 9 can monitor users' browsing activity, e.g., when a browser is closed, the movements made on a webpage and when one is refreshed, etc. Additionally, the malicious extension can steal Internet cookies. It also has keylogging abilities (i.e., keystroke recording), which can be used to obtain usernames/passwords, credit card numbers, and other vulnerable information.

This extension can run intrusive ad campaigns (i.e., operate as adware). Cloud 9 is capable of stealthily opening webpages on a browser, and this functionality is often used to access malicious sites and further the infection.

As the infection progresses, this malware gains control over the machine - and if the user has admin privileges, they can be abused to create new accounts, access/manipulate/delete data, and so forth - without limitation. Hence, Cloud 9 can operate as a RAT - a type of malicious software that enables remote access and control over devices.

Cloud 9 can obtain the data copied into the clipboard, and this feature is triggered whenever the victim pastes content. The malware can also abuse system resources to generate cryptocurrency (i.e., operate as a cryptominer).

Additionally, Cloud 9 can add infected devices into a botnet, with which it can then launch DDoS attacks and thus disrupt various processes (e.g., websites, services, companies, etc.).

To summarize, Cloud 9 infections can result in severe privacy issues, data loss, hardware damage, significant financial losses, and identity theft.

Malware in general

We have analyzed thousands of malware samples; Escanor (Esca) RAT, Windows Calculator malware, YamaBot, Manjusaka, and Lightning Stealer are some of our latest articles on this topic.

Malicious software can have a broad range of functionalities, which can be in varied combinations. However, regardless of how malware operates - its presence on a system endangers device integrity and user safety. Therefore, we strongly advise eliminating all threats immediately upon detection.

How did Cloud 9 infiltrate my computer?

Cloud 9 has been observed being proliferated via fake Adobe Flash Player update websites. However, since it has been available on hacker forums for several years - how the malware is proliferated depends on the cyber criminals using it at the time.

Generally, malicious software is spread using phishing and social engineering tactics. These programs are usually disguised as or bundled with ordinary content. Malicious files can be archives, executables, PDF and Microsoft Office documents, JavaScript, etc. When a virulent file is executed, run, or otherwise opened - the infection chain is triggered.

Malware is widely proliferated via drive-by (stealthy/deceptive) downloads, online scams, malicious attachments/links in spam emails and messages, untrustworthy download sources (e.g., unofficial and freeware websites, P2P sharing networks, etc.), online scams, malvertising, illegal software activation ("cracking") tools, fake updates, and so on.

How to avoid installation of malware?

We highly recommend being careful with incoming mail. The attachments and links present in suspicious/irrelevant emails and messages - must not be opened since that can result in an infection. We also advise being vigilant when browsing - as illegitimate and malicious material usually appears harmless.

Another recommendation is to download only from official/verified channels. Furthermore, all programs must be activated and updated using functions/tools provided by genuine developers, as illegal activation tools ("cracks") and fake updaters may contain malware.

It is essential to have a dependable anti-virus installed and kept up-to-date. Security software must be used to run regular system scans and to remove detected threats and issues. If you believe that your computer is already infected, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

IMPORTANT NOTE! Before and after removing the Cloud 9 JavaScript BotNet malware we strongly suggest to reset your Internet web browser.

Screenshot of VirusTotal detections of the malicious installer containing Cloud 9 malware:

Screenshot of Cloud 9 malware promoted on hacker forums:

How to remove malware manually?

Most trojan infections can be removed by running a full system scan with Combo Cleaner. The full manual procedure below is for cases where automatic removal failed, where you want to verify a scan caught everything, or where the threat has multiple persistence points.

Tools you'll need

Combo Cleaner Antivirus 7-days free trial

Recommended primary scanner. VB100 certified. The 7-day free trial is available.

Microsoft Defender Offline Free · built-in

Built into Windows. Boots to a clean environment to catch rootkits.

Process Explorer Free

From Microsoft Sysinternals. Better than Task Manager - shows full paths and signatures.

Autoruns Free

From Microsoft Sysinternals. Lists every place malware can persist on your system.

Microsoft Safety Scanner (MSERT) Free

Official Microsoft on-demand scanner. Always-current signatures - expires every 10 days.

Phase 1~ 5 min

Contain - limit the damage

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1

Disconnect from the network

30 secNo tool needed

Unplug your Ethernet cable and turn off Wi-Fi. If you're on a laptop, the airplane-mode key works fastest.

Why this matters

Many trojans exfiltrate data - saved browser passwords, banking sessions, screenshots - and accept remote commands. Cutting the network stops both immediately. Keep it disconnected until Phase 4.

2

Boot into Safe Mode with Networking

3 min

Safe Mode loads a minimal set of drivers and stops most malware from auto-running. "With Networking" lets you download tools - re-enable Wi-Fi only after you've booted in.

Windows 11

Open Settings → System → Recovery. Click Restart now next to Advanced startup.

Your computer will restart into the "Choose an option" menu. Click Troubleshoot → Advanced options → Startup Settings → Restart. After the second reboot, press 5 or F5.

Windows 10

Click the Windows logo, hold Shift, click the Power icon and choose Restart. In the Choose an option screen, click Troubleshoot → Advanced options → Startup Settings → Restart. Press F5.

Windows 8

Go to the Start Screen, type Advanced, select Settings → Advanced startup options → Restart now → Troubleshoot → Advanced options → Startup settings → Restart → F5.

Note: Windows 8 reached end-of-life in January 2023 - running on it puts you at much higher risk of reinfection.

Windows 7

Click Start → Shut Down → Restart → OK. As the system boots, press F8 repeatedly until the Windows Advanced Options menu appears, then choose Safe Mode with Networking.

Note: Windows 7 reached end-of-life in January 2020 - running on it puts you at much higher risk of reinfection.

Phase 2~ 15 min

Identify - find what's hiding

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3

Inspect running processes with Process Explorer

Tool: Process Explorer5 min

Download Process Explorer from Microsoft Sysinternals. Run it as Administrator. Click Options → Verify Image Signatures and View → Lower Pane View → DLLs.

Sort by "Verified Signer." Anything unsigned running from %AppData%, %LocalAppData%, %Temp%, or %ProgramData% is suspicious. Right-click → Properties to see the full image path. Right-click → "Search Online" to look up unfamiliar process names.

Why not just Task Manager

Task Manager hides full file paths, doesn't show digital signatures, and groups processes in ways that make malware easy to miss. Process Explorer is the same tool Microsoft engineers use.

4

Map every persistence point with Autoruns

Tool: Autoruns 14.x10 min

Download Autoruns. Right-click Autoruns.exe and choose Run as administrator - without elevation, Autoruns can't inspect protected registry hives.

In the menu, open Options → Hide Microsoft Entries and Options → Hide Empty Locations, then click Refresh.

Modern trojans don't just live in startup. Walk through these tabs and look for unsigned or unfamiliar entries:

• Logon - classic Run/RunOnce keys
• Scheduled Tasks - frequent hiding spot, especially tasks with PowerShell, MSHTA, or rundll32 actions
• Services - unsigned services in non-Microsoft folders
• WMI - Event Subscriptions are a stealthy persistence mechanism (MITRE T1546.003)
• Image Hijacks - Image File Execution Options "Debugger" abuse
• AppInit - DLLs loaded into every GUI process
• Browser plug-ins - unsigned add-ons across all installed browsers

Pro tip

Right-click any suspicious entry → "Jump to Image" to see the actual file. Right-click → "Search Online" opens VirusTotal for the file hash. Don't delete yet - just write down the file paths and entry names. We'll remove them after the scans.

5

Check the hosts file and DNS settings

3 minBuilt into Windows

Trojans often redirect bank, antivirus, and update domains to attacker-controlled servers by editing the hosts file or DNS settings.

Hosts file: Open Notepad as Administrator and open C:\Windows\System32\drivers\etc\hosts. Legitimate entries are commented with #. Any uncommented IP-to-domain mapping is suspicious - especially redirects for microsoft.com, windowsupdate, or your bank.

DNS settings: Open Command Prompt as Administrator and run ipconfig /all. Confirm your DNS servers point to your ISP, your router, or a known public resolver (Cloudflare 1.1.1.1, Google 8.8.8.8). Then open Settings → Network & internet → [your adapter] → DNS server assignment and verify both DNS and DNS over HTTPS (DoH) settings haven't been hijacked.

Why this matters

A clean PC with hijacked DNS is still a compromised PC. You'll think you're at chase.com and you'll be at the attacker's clone.

Phase 3~ 60-90 min

Remove - three scans, one cleanup

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No single antivirus catches everything. The order below is intentional: offline scan first (catches rootkits before Windows fully loads), then on-demand scanners on the running system, then manual cleanup of anything they missed.

6

Run Microsoft Defender Offline

Tool: Built into Windows15 min

Reboot to normal Windows. Open Windows Security → Virus & threat protection → Scan options. Select Microsoft Defender Antivirus (offline scan) and click Scan now. Your computer will restart into a stripped-down environment and scan before the full operating system loads.

Why this comes first

Rootkits and bootkits hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can hide itself.

Recommended antivirus

Combo Cleaner

VB100 certified. Includes anti-trojan, registry/persistence scanning, anti-spyware in one pass. The 7-day free trial is available.

Download Combo Cleaner

7

Run Combo Cleaner full system scan

Tool: Combo Cleaner20-40 min

Install Combo Cleaner and run a full system scan (not the quick scan). Let it complete fully, review the detected threats, and apply the recommended actions. Combo Cleaner will quarantine known trojans and registry persistence.

8

Run Microsoft Safety Scanner as a second-opinion scan

Tool: Microsoft Safety Scanner15 min

Download Microsoft Safety Scanner (MSERT.exe), Microsoft's free on-demand tool. The binary expires every 10 days, which means every download has the latest signatures. Run a full scan after Combo Cleaner to catch anything one engine alone might miss.

Why a second scan

Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the single most underused verification step in malware removal.

9

Manually remove anything still listed in Autoruns

Tool: Autoruns10 min

Reopen Autoruns. Anything you flagged in Step 4 that's still present hasn't been caught by the automated scans. For each remaining suspicious entry: right-click → Delete in Autoruns (this removes the persistence registration), then navigate to the file path and delete the actual file. Empty the Recycle Bin.

Important

Some malware files reappear after deletion because something else on the system recreates them. If you delete a file and it returns within minutes, you have a remaining persistence point that Autoruns didn't show - usually a service or scheduled task running under SYSTEM. Re-run the scans from Steps 6-8 or proceed to a clean install (see end of guide).

Phase 4~ 15 min

Recover - restore browsers and security

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10

Reset browsers and clear notification permissions

5 min

Trojans and adware frequently hijack browsers - change the default search engine, install rogue extensions, or grant themselves notification permissions to keep displaying scam pop-ups even after the malware is gone.

• Chrome: visit chrome://settings/reset and click "Restore settings to their original defaults." Then visit chrome://settings/content/notifications and remove any unfamiliar sites.
• Edge: visit edge://settings/reset. Then check edge://settings/content/notifications.
• Firefox: open about:support and click Refresh Firefox (Firefox uses "Refresh," not "Reset"). Then check Settings → Privacy & Security → Permissions → Notifications.

Review installed extensions in each browser and remove anything you don't recognize, especially extensions you didn't install yourself.

11

Re-enable Defender, Tamper Protection, and update everything

10 min

Many trojans disable security software. Open Windows Security → Virus & threat protection → Manage settings and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all turned on. Tamper Protection prevents malware from disabling Defender silently.

Then run Windows Update (Settings → Windows Update → Check for updates) and update your browsers and applications. The infection vector that let the trojan in originally usually involves outdated software.

Phase 5~ 15 min + 7 days

Verify & secure

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12

Change passwords from a clean device

20 min⚠ Critical

If the trojan was an info-stealer (Lumma, RedLine, Vidar, and similar are extremely common), assume every password saved in your browser is compromised. Change them from a different, known-clean device - your phone is fine if it's not infected.

Recommended order:

1. Primary email first - it's the recovery hub for everything else
2. Banking and financial accounts
3. Password manager master password (if you use one)
4. Social media, shopping, and remaining accounts

Where available, enable phishing-resistant multi-factor authentication (passkeys / FIDO2 hardware keys / authenticator apps) - SMS-based MFA is bypassable by sophisticated attackers.

13

Verify the clean and monitor for 7 days

5 min + 1 week monitoring

Reconnect to the network and run one final full scan with Combo Cleaner. Open Task Manager (Ctrl + Shift + Esc) and switch to the Startup apps tab - confirm nothing suspicious has reappeared.

Over the next 7 days, watch for symptom recurrence: unexpected high CPU usage, unknown processes returning, browser redirects, or pop-ups. If anything returns, you missed a persistence point and the procedure needs to be repeated - or you may have a deeper compromise that requires a clean install.

When to clean install Windows instead

Manual removal isn't always the right answer. Reinstalling Windows from scratch is the only way to be 100% certain when:

• The malware reappears after every removal attempt
• A bootkit or UEFI rootkit was detected (this class of threat sits below the operating system and survives a normal Windows reinstall)
• A confirmed credential-theft trojan ran with administrator privileges (Lumma, RedLine, Vidar) - the system likely has multiple unknown payloads
• The PC is used for online banking, business email, or anything where partial doubt isn't acceptable

A clean install is a 30-60 minute process: Windows 11 reinstall via Settings → System → Recovery → Reset this PC → Remove everything → Cloud download. Back up documents to external storage first, scan the backup with Combo Cleaner before restoring it, and reinstall applications fresh - never restore them from a backup of the infected system.

Important: Manual removal requires advanced computer skills. If you're not confident identifying system files from malicious files, run an automated scan with Combo Cleaner and Windows Defender and stop there - that path catches the vast majority of consumer trojans without the risk of breaking Windows by deleting the wrong file.

Frequently Asked Questions (FAQ)

My computer is infected with Cloud 9 malware, should I format my storage device to get rid of it?

Most malicious programs can be removed without resorting to such drastic measures.

What are the biggest issues that Cloud 9 malware can cause?

The threats depend on a program's features and the cyber criminals' aims. Cloud 9 infections can lead to the attackers gaining close to user-level control over devices. This malware can steal data, launch DDoS attacks, mine cryptocurrency, and perform various other harmful activities.

Generally, such infections can result in serious privacy issues, data loss, hardware damage, financial losses, and identity theft.

What is the purpose of Cloud 9 malware?

The goal of most malicious programs is to generate profit. However, cyber criminals can also use this software to amuse themselves, carry out personal vendettas, disrupt processes (e.g., sites, services, companies, etc.), and even launch politically/geopolitically motivated attacks.

How did Cloud 9 malware infiltrate my computer?

Cloud 9 has been notably spread via fake Adobe Flash Player update websites. However, it is likely distributed using other methods as well.

In addition to fake updaters, malware is also proliferated via drive-by downloads, online scams, spam emails and messages, malvertising, untrustworthy download sources (e.g., freeware and free file-hosting sites, P2P sharing networks, etc.), illegal program activation tools ("cracks"), and so on. Furthermore, some malicious programs can self-spread through local networks and removable storage devices (e.g., external hard drives, USB flash drives, etc.).

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner can detect and eliminate most of the known malware infections. It is essential for detection to perform full system scans - since high-end malicious programs typically hide deep within systems.