What sort of email scam is "Outstanding Invoice"

What kind of email is "Outstanding Invoice"?

We have examined this email and determined it is a phishing scam. The message is disguised as a document notification from DocuSign, falsely claiming that an outstanding invoice is ready for the recipient's review and signature. Clicking the provided button leads to a fake webmail login page designed to steal email credentials. This email should be ignored.

"Outstanding Invoice" email scam overview

The email arrives under the subject line "Outstanding Invoice" and is styled to resemble an official DocuSign notification. It claims a document is ready for review and urges the recipient to click a "REVIEW & SIGN DOCUMENT" button.

An "Audit Compliance" notice is used to create urgency, warning that the invoice payment deadline has already passed and that legal action may follow. This pressure tactic is intended to make recipients act quickly without stopping to question the message.

Clicking the button does not open any real invoice. Instead, the recipient is taken to a fake webmail login page hosted on Google's Firebase Storage. The page imitates the appearance of a cPanel Webmail interface, asking for an email address and password.

Any credentials entered there go directly to the scammers. A stolen email account can be used to access other services linked to that address, send phishing emails to the victim's contacts, or be sold on criminal marketplaces.

DocuSign is a legitimate and widely used document signing platform. It has no connection to this scam. The fraudsters simply borrow its name and visual identity to make the email look trustworthy.

Email scams in general

In summary, this is a phishing scam that impersonates DocuSign to trick recipients into submitting their email credentials on a fraudulent login page. There is no invoice. The whole premise is fabricated to gain unauthorized access to email accounts.

Scams of this nature are sometimes also used to distribute malware through malicious attachments or links.

More examples of similar scam emails are Order Specification, Presentation & Drawing, Your Payslip Is Available, and Account Security Notice.

How do spam campaigns infect computers?

Cybercriminals distribute malware via email using malicious attachments or harmful links. Common attachment types include executables, Office documents, archives, PDFs, and script files. Opening these - or enabling features such as malicious macro commands in a document - can trigger a malware installation on the recipient's device.

Links in spam emails may redirect users to sites that silently download malicious software, or that prompt the victim to download and run it manually. As a rule, some form of user interaction is required before a system is compromised.

How to avoid installation of malware?

Exercise caution with emails from unknown or unexpected senders, especially those that pressure you into opening attachments or clicking links. If a message seems suspicious, do not interact with it.

Only download software from official developer websites and verified app stores. Avoid pirated programs, crack tools, and key generators, as these are common channels for spreading malware.

Keep your operating system and all installed applications up to date. Use reputable antivirus software and avoid granting notification permissions to sites you do not recognize. If you have already interacted with a suspicious link or file, we recommend running a scan with Combo Cleaner Antivirus for Windows to detect and remove any threats that may have been installed.

Text presented in the "Outstanding Invoice" email letter:

Subject: Outstanding Invoice

Outstanding Invoice                                          Secure Portal

Outstanding Invoice is ready for your review
DOC

Outstanding Invoice_'7515560197' [redacted].docx
2.4 MB

[REVIEW & SIGN DOCUMENT]

Audit Compliance: Please review invoice and arrange payment as soon as possible as due time already exceeded, to avoid taking legal actions.

DocuSign, Inc.
221 Main Street, Suite 1550, San Francisco, CA 94105
Secured by DocuSign © 2026

A fake webmail login page used in this scam:

Instant automatic malware removal:

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Quick menu:

• What is Outstanding Invoice phishing scam?
• Types of malicious emails.
• How to spot a malicious email?
• What to do if you fell for an email scam?

Types of malicious emails:

Phishing Emails

Most commonly, cybercriminals use deceptive emails to trick Internet users into giving away their sensitive private information, for example, login information for various online services, email accounts, or online banking information.

Such attacks are called phishing. In a phishing attack, cybercriminals usually send an email message with some popular service logo (for example, Microsoft, DHL, Amazon, Netflix), create urgency (wrong shipping address, expired password, etc.), and place a link which they hope their potential victims will click on.

After clicking the link presented in such email message, victims are redirected to a fake website that looks identical or extremely similar to the original one. Victims are then asked to enter their password, credit card details, or some other information that gets stolen by cybercriminals.

Emails with Malicious Attachments

Another popular attack vector is email spam with malicious attachments that infect users' computers with malware. Malicious attachments usually carry trojans that are capable of stealing passwords, banking information, and other sensitive information.

In such attacks, cybercriminals' main goal is to trick their potential victims into opening an infected email attachment. To achieve this goal, email messages usually talk about recently received invoices, faxes, or voice messages.

If a potential victim falls for the lure and opens the attachment, their computers get infected, and cybercriminals can collect a lot of sensitive information.

While it's a more complicated method to steal personal information (spam filters and antivirus programs usually detect such attempts), if successful, cybercriminals can get a much wider array of data and can collect information for a long period of time.

Sextortion Emails

This is a type of phishing. In this case, users receive an email claiming that a cybercriminal could access the webcam of the potential victim and has a video recording of one's masturbation.

To get rid of the video, victims are asked to pay a ransom (usually using Bitcoin or another cryptocurrency). Nevertheless, all of these claims are false - users who receive such emails should ignore and delete them.

How to spot a malicious email?

While cyber criminals try to make their lure emails look trustworthy, here are some things that you should look for when trying to spot a phishing email:

• Check the sender's ("from") email address: Hover your mouse over the "from" address and check if it's legitimate. For example, if you received an email from Microsoft, be sure to check if the email address is @microsoft.com and not something suspicious like @m1crosoft.com, @microsfot.com, @account-security-noreply.com, etc.
• Check for generic greetings: If the greeting in the email is "Dear user", "Dear @youremail.com", "Dear valued customer", this should raise suspiciousness. Most commonly, companies call you by your name. Lack of this information could signal a phishing attempt.
• Check the links in the email: Hover your mouse over the link presented in the email, if the link that appears seems suspicious, don't click it. For example, if you received an email from Microsoft and the link in the email shows that it will go to firebasestorage.googleapis.com/v0... you shouldn't trust it. It's best not to click any links in the emails but to visit the company website that sent you the email in the first place.
• Don't blindly trust email attachments: Most commonly, legitimate companies will ask you to log in to their website and to view any documents there; if you received an email with an attachment, it's a good idea to scan it with an antivirus application. Infected email attachments are a common attack vector used by cybercriminals.

To minimise the risk of opening phishing and malicious emails we recommend using Combo Cleaner Antivirus for Windows. 

Example of a spam email:

What to do if you fell for an email scam?

• If you clicked on a link in a phishing email and entered your password - be sure to change your password as soon as possible. Usually, cybercriminals collect stolen credentials and then sell them to other groups that use them for malicious purposes. If you change your password in a timely manner, there's a chance that criminals won't have enough time to do any damage.
• If you entered your credit card information - contact your bank as soon as possible and explain the situation. There's a good chance that you will need to cancel your compromised credit card and get a new one.
• If you see any signs of identity theft - you should immediately contact the Federal Trade Commission. This institution will collect information about your situation and create a personal recovery plan.
• If you opened a malicious attachment - your computer is probably infected, you should scan it with a reputable antivirus application. For this purpose, we recommend using  Combo Cleaner Antivirus for Windows.
• Help other Internet users - report phishing emails to Anti-Phishing Working Group, FBI’s Internet Crime Complaint Center, National Fraud Information Center and U.S. Department of Justice.

Frequently Asked Questions (FAQ)

Why did I receive this email?

Phishing emails like this are not targeted. They are sent in bulk to large lists of addresses gathered through data breaches, fake sign-up forms, and similar methods.

I have provided my personal information when tricked by this email, what should I do?

Change the password for the email account you entered credentials for immediately. Also update the passwords of any other accounts that share the same login details.

If you also provided financial or identification data, contact the relevant banks or authorities as soon as possible.

I have downloaded and opened a malicious file attached to an email, is my computer infected?

Executable files (.exe and similar) can compromise a device almost immediately upon being opened. Document formats such as PDFs or Word files generally require an additional step - like enabling macros or running an embedded installer - before malware activates.

The level of risk depends on the file type and how the user interacts with it.

I have read the email but did not open the attachment, is my computer infected?

No. Reading or previewing an email is harmless on its own. A device can only be compromised if the user clicks a malicious link, opens a dangerous attachment, or otherwise acts on the email's harmful content.

Will Combo Cleaner remove malware infections that were present in email attachment?

Yes, Combo Cleaner is able to detect and remove most known malware. Running a full system scan is strongly recommended, as some more advanced threats may hide deeper in the system and require thorough inspection to be found and eliminated.