How to remove malware infections caused by Win/Exploit.CVE-2017-11882

What is Win/Exploit.CVE-2017-11882?

Win/Exploit.CVE-2017-11882 is an exploit designed to abuse a vulnerability (CVE-2017-11882) in Microsoft Equation Editor, a component of the Microsoft Office programs. While this weak link has been addressed in the latest MS versions, unpatched ones remain vulnerable.

This exploit is used as the initial point of entry for various malicious programs. When users open a malicious document tailored to use the CVE-2017-11882 vulnerability, the infection process is triggered, culminating in malware infiltration of the system. Our researchers have sampled a Win/Exploit.CVE-2017-11882 exploit using document from VirusTotal.

Win/Exploit.CVE-2017-11882 overview

Theoretically, exploits like Win/Exploit.CVE-2017-11882 can be used to infect systems with any malware. Therefore, the potential threats posed by such infections are vast.

To expand upon the most common malicious software classifications: ransomware operates by encrypting data and/or locking the device's screen - to demand payment for the decryption/ access recovery. Cryptominers are a type of malware that use system resources to generate cryptocurrency.

The term "trojan" encompasses malicious programs with a broad range of harmful functionalities. Trojans can operate as loaders (download/install additional malware), spyware (record keystrokes [keylogging], audio/video via microphones and cameras, etc.), RATs - Remote Access Tools (enable access/control over infected machines), stealers (exfiltrate information and files), clippers (replace copy-paste buffer data), and so on.

To summarize, Win/Exploit.CVE-2017-11882 could infect systems with malware possessing any of the aforementioned malicious capabilities. Hence, opening a virulent document that uses the CVE-2017-11882 vulnerability can result in a malware infection that could cause decreased system performance or failure, permanent data loss, hardware damage, severe privacy issues, financial losses, and identity theft.

If you suspect that your system is already infected, we highly recommend using an anti-virus to remove the threats immediately.

Similar infection examples

We have analyzed thousands of malware samples. Purple Fox, BazarLoader, Groooboor, and BLADABINDI are just a few examples of those capable of infiltrating additional malicious programs into systems.

Malicious software of this kind can be designed to inject devices with any malware or a specific program. Like all malicious programs, this type can have varied functionalities, not limited to malware infiltration. However, regardless of how this software operates, its presence on a system endangers device integrity and user safety.

How did Win/Exploit.CVE-2017-11882 infiltrate my computer?

The Win/Exploit.CVE-2017-11882 exploit is incorporated in malicious documents, which are most commonly distributed through spam campaigns. Scam emails and other deceptive messages can contain such files as attachments or links (leading to websites designed to lure users into download/installation or ones capable of doing so stealthily).

The malware download/installation process is triggered when a document that abuses the CVE-2017-11882 vulnerability is opened in unpatched Microsoft Office versions.

It is pertinent to mention that infectious files spread through spam mail can be in various formats, e.g., PDF documents, archives (RAR, ZIP, etc.), executables (.exe, .run, etc.), JavaScript, and so forth.

In general, malware is proliferated using various phishing and social engineering techniques. Hence, documents using the Win/Exploit.CVE-2017-11882 exploit could have other origins aside from spam mail. Malicious software is often offered (under the guise of ordinary content) on dubious download channels, e.g., Peer-to-Peer sharing networks, unofficial, free file-hosting, and freeware websites, etc.

How to avoid installation of malware?

We strongly advise against opening the attachments and links present in suspicious and irrelevant emails/messages, as they can contain malware. Additionally, we recommend using the latest versions of Microsoft Office.

Another recommendation is downloading only from official and trustworthy channels. It is just as important to activate and update software with tools provided by genuine developers.

We must emphasize that having a dependable anti-virus installed and updated is paramount to device/user safety. Security programs must be used to run regular system scans and to remove 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.

Screenshot of a malicious document that uses Win/Exploit.CVE-2017-11882 ("Leiser Order .xlsx"):

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 Win/Exploit.CVE-2017-11882 malware, should I format my storage device to get rid of it?

No, Win/Exploit.CVE-2017-11882 infections can be removed without resorting to such drastic measures.

What are the biggest issues that Win/Exploit.CVE-2017-11882 malware can cause?

Win/Exploit.CVE-2017-11882 is an exploit - it is designed to abuse a vulnerability in Microsoft Office programs to infect the device with malware. The infiltrated malicious program could be a trojan, ransomware, cryptominer, or a different type. The threats posed by such infections include - decreased system performance or failure, hardware damage, data loss, serious privacy issues, financial losses, and identity theft.

What is the purpose of Win/Exploit.CVE-2017-11882 malware?

Most cyber criminals use malware to generate revenue. However, other reasons are possible, e.g., attackers' amusement, process disruption (e.g., sites, services, organizations, etc.), political/geopolitical motivations, personal vendettas, and so on.

How did Win/Exploit.CVE-2017-11882 malware infiltrate my computer?

Win/Exploit.CVE-2017-11882 is incorporated into document files, and such are commonly spread through spam emails. However, other sources are possible. Generally, malware is proliferated through spam mail, drive-by (stealthy and deceptive) downloads, online scams, freeware and third-party download websites, Peer-to-Peer sharing networks, illegal software activation ("cracking") tools, fake updates, and so on. Some malicious programs are also capable of self-spreading 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. However, performing a complete system scan is vital - since high-end malicious software usually hides deep within systems.