Malware: Viruses in Attachments in Emails- What You Need to Know

An email urges you to read the attachment, fill out the attach form, etc.

Have you received an email with a file attached, and it is not something you were expecting to receive? 

It is a scam and malware.  If you click to open the attached file (typically, it is a zip file or an EXE), you will open a virus or other malware.  This type of attack has skyrocketed.  It is not uncommon to receive several emails a day containing viruses or trojan software contained in a zip or exe file.

Norton, the anti-virus company defines this sort of attachment as "malware", saying on their website:

"Malware is a category of malicious code that includes viruses, worms, and Trojan horses. Destructive malware will utilize popular communication tools to spread, including worms sent through email and instant messages, Trojan horses dropped from web sites, and virus-infected files downloaded from peer-to-peer connections. Malware will also seek to exploit existing vulnerabilities on systems making their entry quiet and easy."

Opening the attached file can install a virus or trojan on the user's computer. Once installed, a virus and destroy your files, replicate itself, spam your friends and more. A trojan can send your confidential, personal information to malicious servers and may download other malware.

The scammers rely on the fact that many recipients may open the attachment out of simple curiosity or concern. You should always be very cautious of any unsolicited emails that claim that a package delivery has failed or been returned. No legitimate delivery company will send notice of a failed delivery via an unsolicited email. Especially not with an attachment.


Recommendations- What to do:

See this page for detailed instructions on what to do.

Here are some general directions:.

  • Only open email or IM attachments that come from a trusted source and that are expected
  • Use an anti-virus/anti-spam package (we recommend Norton 360 or Norton Internet Security scan all attachments prior to opening. Click here to see Norton 360 2013 on .
  • Delete the messages without opening any attachments
  • Do not click on links in emails that come from people you do not know and trust, even if it looks like it comes from a company you know.
  • Keep your anti-virus software up to date
  • Keep your operating system up to date with current security patches. Click here for an article that describes how to do this.

And please let us know about any suspicious calls or emails you receive.  We look for patterns so that we can alert the authorities and victims to new scams, before it is too late!

Definitions: What are viruses, trojans, worms and more?

 Malware is a category of malicious software code that includes viruses, worms, bots, backdoors and Trojan horses. Malware uses popular communication tools to spread, including viruses and worms that are sent through email and instant messages, Trojan horses in email attachments or received when you visit a corrupted website, and virus-infected files downloaded from file sharing P2P connections. This can be confusing, so here is a simple breakdown. See this article from CISCO for a more detailed description.


A computer virus propagates itself by inserting a copy of itself onto your computer. Viruses can range in severity from causing mildly annoying effects to damaging data files or software. Almost all viruses are attached to an executable file, which means the virus may be on your computer or in an email, but will not be active or able to spread until you run it, click on it, or open the file or attachment.


Computer worms are similar to viruses in that they reproduce copies of themselves and can cause the similar damage. But worms are standalone software and do not require the user to open an attachment (although they can) - often they take advantage of weaknesses in operating systems to spread from computer to computer throughout a network (home or company)


A Trojan is named after the wooden horse the Greeks used to enter Troy. It is a harmful file that looks legitimate, such as "Attached is your invoice. Click here to open it.". Users are typically tricked into loading and executing it on their systems. After it is activated, it can achieve any number of attacks on the host, from irritating the user (popping up windows or changing desktops) to damaging the host (deleting files, stealing data, or activating and spreading other malware, such as viruses). Trojans are also known to create back doors to give malicious users access to the system.


"Bot" comes from the word "robot" and is an automated process that interacts with other network services. A typical good use of bots is to gather information (such as web crawlers), or interact automatically with instant messaging (IM), Internet Relay Chat (IRC), or other web interfaces. They may also be used to interact dynamically with websites. Bots can be used for either good or malicious intent. A malicious bot is self-propagating malware designed to infect a host and connect back to a central server that may control an entire network of compromised devices, or "botnet. Bots can include the ability to log keystrokes, gather passwords, capture and analyze packets, gather financial information, launch DoS attacks, relay spam, and open back doors on the infected host.


A back door is an undocumented way of getting into a computer system, bypassing the normal security logon mechanisms. Some back doors are placed in the software by the original programmer and others are placed on systems through a system compromise, such as a virus or worm. Usually, attackers use back doors for easier and continued access to a system after it has been compromised. This is common when software makes your computer a "zombie".

For a comprehensive list of national and international agencies to report scams, see this page.

How to prevent malware

Scammer try to trick you into clicking on links in emails they send you. Doing that will download viruses, spyware, and other unwanted software - often by bundling it with popular free downloads. To reduce your risk of downloading malware:

  • Install and update security software, and use a firewall. See this page for recommendations.
  • Set your security software, internet browser, and operating system (like Windows or Mac OS X) to update automatically.
  • Donít change (reduce) your browserís security settings. You can minimize "drive-by" or bundled downloads if you keep your browserís default security settings.
  • Pay attention to your browserís security warnings. Many browsers come with built-in security scanners that warn you before you visit an infected webpage or download a malicious file.
  • Instead of clicking on a link in an email, type the URL of a trusted site directly into your browser. Criminals send emails that appear to be from companies you know and trust. The links may look legitimate, but clicking on them could download malware or send you to a scam site. If you hover your mouse over a link in an email, you can see what the real url is.  If it does not match the domain of the real destination, you know it is a scam!
  • Donít open attachments in emails unless you know who sent it and what it is. Opening the wrong attachment - even if it seems to be from friends or family - can install malware on your computer.
  • Get well-known software directly from the source. Sites that offer lots of different browsers, PDF readers, and other popular software for free are more likely to include malware.
  • Read each screen when installing new software. If you donít recognize a program, or are prompted to install additional ďbundledĒ software, decline the additional program or exit the installation process.
  • Donít click on popups or banner ads about your computerís performance. Scammers insert unwanted software into banner ads that look legitimate, especially ads about your computerís health. Avoid clicking on these ads if you donít know the source.
  • Scan USBs and other external devices before using them. These devices can be infected with malware, especially if you use them in high traffic places, like photo printing stations or public computers.
  • Talk about safe computing. Tell your friends and family that some online actions can put the computer at risk: clicking on pop-ups, downloading "free" games or programs, opening chain emails, or posting personal information.
  • Back up your data regularly. Whether it's your taxes, photos, or other documents that are important to you, back up any data that you'd want to keep in case your computer crashes.

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