Computer Viruses

What is a computer virus?

A computer virus or malware is a commonly used term to describe all types of malicious software including Trojans, worms, adware, and spyware. Each have slightly different functions, but usually either try and damage the software on your computer, or send information about your computer usage to an outside source over the internet. The details of each type are explained below:

Types of computer viruses

Trojans: A Trojan, as the name suggests, pretends to be something good, like virus scanning software or other useful applications. In reality they run malicious programs in the background that can perform any number of functions, like allowing an outside user to copy your files, see your browsing history, or even take remote control of your computer.

Worms: A computer worm is a self-replicating computer program. It uses a network to send copies of itself to other computers on the network, and it may do so without any user intervention. Unlike a virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, if only by consuming bandwidth, whereas viruses almost always corrupt or devour files on a targeted computer.

Adware: Adware or advertising-supported software is any software package which automatically plays, displays, or downloads advertisements to a computer after the software is installed on it or while the application is being used. Adware is usually seen by the developer as a way to recover development costs, and in some cases it may allow the software to be provided to the user free of charge or at a reduced price. As a result, the advertisements may be seen by the user as interruptions, annoyances or as distractions from the task at hand.

Spyware: Spyware is computer software that is unknowingly installed on a personal computer to collect information about a user, their computer or browsing habits without the user's informed consent. Spyware programs can collect various types of personal information, such as Internet surfing habits and sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software and redirecting Web browser activity. Spyware is known to change computer settings, resulting in slow connection speeds, different home pages, and/or loss of Internet or functionality of other programs.

How can my computer become infected?

Unfortunately, there are many ways your computer can become infected. Some of the main causes to an infected computer included: illegally downloading music and movies, clicking on ads, browsing to compromised websites, and in general not being cautious when it comes to web browsing. Be sure to follow the safe browsing habits and remember, it's always better to be safe then to be sorry.

What are the symptoms of a virus?

There is a wide variety of virus symptoms that differ based on what type of infection you have and how far the virus has progressed. A list of common symptoms is listed below:

  • Speed decrease
  • Unexplained freezing/crashing
  • Programs that won’t launch
  • New programs won’t install
  • Computer has trouble booting windows
  • Internet access is blocked (completely or certain sites)
  • Desktop/appearance/screen saver and other visual settings are changed unexpectedly
  • Unable to open files or folders
  • Files or folders are deleted unexpectedly
  • False pop-ups that appear warning you about viruses
  • Deteriorating condition over a period of a few days to a few weeks (viruses that download more malicious software as time goes on)
  • Unable to print documents
  • Your hard disk runs out of free space (this comes from an infected file making copies of itself)

How can I protect myself?

  • For a personally owned computer, use ClamXAV and Windows Defender/Security Essentials. For instructions on installing and basic use of these products please go here. If your computer is university owned, please talk to your computer support group for assistance.
  • Keep your computer's operating system up to date using Windows Update or Software Update on Mac.
  • Read "How to recognize a Fake Virus Alert Message."
  • NEVER use file sharing programs to download games, music, movies, TV shows, etc. A large majority of the files shared on this network are infected.
  • NEVER click advertisements on the Internet.
  • NEVER give anyone your password.
  • NEVER respond to SPAM.
  • READ all warnings very carefully.
  • EDUCATE yourself, your friends and family about infections.
  • NEVER click OK or cancel to warnings like this:

How can I scan and remove a virus infection?

The first order of business is to get anti-virus software. Students and faculty can download ClamXAV and Windows Defender/Security Essentials for free, but the protection shouldn't stop there. We also recommend downloading other virus scanning tools, here at the OSU Computer Helpdesk we often use Malwarebytes and SUPERAntiSpyware both of which are available for free.

Click HERE to watch a tutorial about running a virus scan with Malwarebytes.

After obtaining the software simply run the program and have it scan for viruses. A good habit to exercise before each scan is to double check that the software's definitions are up-to-date. In order to update the definitions there should be either a tab or button that relates to updating the software, e.g. "Check for Updates online."

CryptoLocker - Dangerous ransomware

What is CryptoLocker?

CryptoLocker is malicious software that encrypts your data files (word, powerpoint, pictures, music, videos, etc.). The nefarious individuals then hold your data for ransom and try to extort money from you.


What computers are at risk?

All computers using Windows XP 2, Vista, 7, 8 and 8.1. This includes any Apple or Linux based computers running Windows in a virtual environment like Bootcamp, Parallels or VMWare.


What is encryption?

Encryption encodes your data so only you and authorized people or authorized websites can read the data. Example – When you use a banking website that has “https” in the address bar, the information you transmit to and from that website is encrypted/encoded.


Why is it dangerous?

The encryption designed to safeguard your data is used against you when CryptoLocker infects your computer. Your data files are encrypted with a unique key that only the malicious people/hackers have access to. Encryption can not be broken at this point in time without the key. When your data is encrypted and the key is lost, the data is essentially lost forever.


How can I protect my data?

  1. Backup your data to another location (network drive, external hard drive, cloud storage, etc.)
    1. Disconnect that drive when you are NOT backing up your data to it.
  2. Consider paying for an online backup solution.
  3. Disconnect all drives that you are not actively using.

What if I think my computer is infected?

  1. Disconnect the computer immediately from ALL networks, wired or wireless.
  2. Contact the proper IT support group.

How can I avoid the malware infection?

  1. Don't go to online porn sites, which are often the source of malware downloads. 
  2. Take care when clicking on adverts; never open Twitter links and attachments from people you don't know or trust.
  3. Personally owned computers - 
    1. Download and run the CryptoPrevent tool - 
    2. More info about that tool can be found here -
  4. Do not download files from Torrenting services. These files are often bundled with malware infections.
  5. Use safe web browsing habits -

How can I protect my computer?

  1.  Make sure your operating system is up-to-date with the latest security patches.
  2. Install the latest versions of your internet browsers and update add-ons such as Java and Adobe Flash. Using a program like Secunia PSI to keep up with those updates is useful.
  3. We suggest installing antivirus software, like ClamXAV for Mac OS and Windows Defender / Security Essentials for Windows, all available for free. Ensure that is updated frequently. Configure it to scan your computer on a weekly basis.
    1. Personal computers -
    2. OSU owned work computers are supported by IT staff. If you have questions about that, please contact your IT support group.

Other sources of helpful information about CryptoLocker

  3. Kaspersky Virus Removal Tool from the following page, requires request form:
  4. Test tool from BleepingComputer - checks your files to see if they have been encrypted:

Fake AntiVirus Warnings

Examples of Fake Warnings

Here are two screenshots of fake warnings. Click an image to view at full size.

If you see a popup like one shown here, your computer may already be infected. Shut it down and take it to the OSU Computer Helpdesk or your IT support staff to resolve the issue.

fake security warning

fake antivirus example

About Fake AntiVirus Warnings

Bad guys prey upon people's fears to steal their money and information. One of their favorite tricks is to tell people that their computer is (or might be) infected, and they are relying on you to respond in a manner that installs a virus on your computer.

In some cases, your computer may already be infected before you see the popup. The safest thing to is shut it down and take it to the OSU Computer Helpdesk or your IT support staff to resolve the issue.

But you can protect yourself before you're affected.

Protect Yourself Before You're Affected

There are three big ways to protect yourself before you're affected.

  1. Download free antivirus software, and keep it up to date (free for home use, too).
  2. Enable your web browser's phishing protection settings, usually found under "Tools" or "Preferences" or "Settings." Call the OSU Computer Helpdesk at 541-737-3474 if you're not sure how to do this.
  3. Get to know the look of pop up messages from your current AV software. If you know what you are looking for, you are much harder to fool. Take note of the name and icon of your anti-virus software and click on pop ups that only come from that program.

There are a few additional steps you can take.

What If I Do See A Warning?

A few things to check for if you are unsure about the message are:

  1. Close and quit the web browser (Chrome, Internet Explorer, Firefox, Safari, etc.) immediately. Do NOT click on OK or cancel. Even a button that says "close" can be deceiving.
  2. Does closing your internet browser make the virus alert go away? Often the pop up window is really embedded on an internet page so if you close your browser it will go away. Alerts like this should always be avoided.

If you think you may have accidentally clicked on a fake antivirus warning, shut down your computer. Students can bring laptops to the Walkup Helpdesk for malware scans, while faculty and staff should contact their IT support staff.

What Happens If My Computer Gets Infected?

The viruses that get installed can:

  • Trick you into entering your credit card information or passwords or personal information.
  • Steal your bank account information and empty out your account.
  • Send spam messages from your email address.
  • Corrupt or destroy your documents.
  • Allow other, stronger infections into your computer.
  • Crash your computer or slow it to a crawl.
  • Infect other computers both on the Internet and on a local network.

Who to Contact

OSU work computer - Please contact your IT support staff.

OSU Students - Contact the OSU Computer Helpdesk.

Self help options for personal computers

Malware Detection at OSU

Oregon State University utilizes a device on our network called FireEye. This device monitors the network for patterns of activity a computer displays when it is infected with malware, or has been compromised by hackers.

When the FireEye device detects signs of malicious activity, it sends an alert to the OSU Computer Helpdesk, who, in turn, sends a notification to the registered owner of the computer. The user is then responsible for contacting the Helpdesk to resolve the issue. This document outlines that notification process.

Please Note: While every attempt will be made to resolve the situation through this process, there may be instances where the availability, confidentiality, or integrity of the OSU network or the data residing therein is placed at risk by the activity discovered on the device. In such cases, network access for that system will be blocked prior to notification.


Notification Process

OSU notifies users when a malware infection is detected on their computer. Users must come in for help, or inform the Helpdesk that the infection has been removed.

Notifications include technical details on the infection and give users information on how to clean their own computers. Please note that the notifications will be from and will be followed with an email from detailing options you have to clean your computer.

Network access disabled notification:

If the user does not come in for help or notify the OSU Computer Helpdesk and they continue to receive notifications from then the user’s network access will be disabled and a notification of the access restriction will be sent.

A user is not typically disabled until after three notifications have been sent, but there are circumstances that will extend the amount of notifications before loss of network access, such as a long period of time between malware notifications from FireEye.


Example Malware Notifications

Below are examples of the notification e-mails sent to users, which can be used as reference to ensure these are not fake emails or phishing attempts.

Example from Security:

Hello [Customer Name],

OSU's network security group has detected malware activity originating from your machine.
This is most likely due to a malware or virus infection on your machine.  Please check you
machine for viruses and malware and remove any infections.  If infections are not removed
and further malware related activity is found on your machine, you risk your network
access being disabled until the infection is removed.

Details about the potential infection are listed below:

Malware last detected: [Date] [Time]
IP: [Customer’s leased IP at time of detection]
Hostname: [Customer’s hostname on network]
MAC Address?: [Customer’s Hardware address]
ONID Username: [Customer username]
Zone: [Zone customer’s computer was assigned to]
Malware: [Type of infection detected]
Attacker's Info: [IP address? and port infection is communicating through]

For more details on this infection, visit

For help removing this infection on your own, see

If you would like assistance removing the infection please contact the OSU Computer
Helpdesk -
Phone: 541-737-3474

Note: This report is for your information and a copy is provided to the OSU Computer


Example from the OSU Computer Helpdesk:

OSU’s Network Security group ( sent you an e-mail recently informing you about a possible malware infection on your computer. The OSU Computer Helpdesk wanted to check in with you and see if you have been able to remove the infection.

Because network security is a priority for personal and network safety, careful procedures are in place to quarantine potential infections. If no response is received from you after multiple notifications, the Helpdesk will disable your network access. Multiple warnings will be provided before access is disabled and it is easy to restore your network access by contacting the Helpdesk to inform them you have cleaned the infection yourself, or for help removing the infection.

Please be aware that if you clean the infection yourself, you must inform the Helpdesk that the infection is resolved. If  you don't respond to this email and your computer is still reporting as being infected, the Helpdesk will disable your network access after three notifications.

Clean it yourself -

You can also find out more information on how to remove infections here:

If you clean your computer, please respond to this email that you have cleaned your computer. If you receive another notice after reporting that you have cleaned the computer your network access will be disabled and you will be notified.

Students with laptops - 

If you still need assistance, please come to our Walk Up Helpdesk, located on the main floor of the Valley Library. It is open 8AM-9PM Monday through Thursday, 8AM-7PM Friday, and 3PM-7PM Sunday. You can also give us a call at 541-737-3474.

Students with desktop computers living in the dorms -

Call the OSU Computer Helpdesk at 541-737-3474 for guidance and further assistance.

If you do not have an anti-virus program on your computer -

You can get ClamXav on your Mac OS device, or Windows Defender / Windows Security Essentials. If you already have an antivirus program, please use Malwarebytes to double check that you do not have viruses on your system.

How to use Malwarebytes - Malwarebytes download page

Anti-virus software to protect yoru computer

You can go to for more information on viruses.

Please let us know if you have any questions or concerns.

If you are forwarding your email to another account, please make sure to check your spam folder for the messages we are contacting you about.

Virus Threats for Macintosh Computers

New Mac Flashback Virus

There is a virus for Mac that has recently started to pick up steam (infected over 600,000 Mac computers worldwide). It is called the Flashback trojan, and relies on a vulnerability in your computer's Java installation. This virus operates in the background, so many users don't know they are infected. Click Here for more details, and steps you can take to see if your computer is infected.


Other Mac Viruses

Currently there are multiple malware programs circulating designed to infiltrate Mac OS. These programs are similarly designed to look like legitimate antivirus programs and tell users that their Mac is heavily infected with viruses. The program then harasses people into providing credit card information to purchase fake anti-virus program to remove the infection. This is a ploy to get your personal information. 

Often times these programs are automatically downloaded but cannot be installed without the permission of the user, by way of an administrator password. People who are not aware of these malware threats can unknowingly install these programs on to their machines. ONLY install programs on your machine that are from trusted publishers and that you have knowingly downloaded. Also, make sure that you have an updated antivirus program on your Mac. Students and Staff of OSU have access to ClamXav, which is a free antivirus program

Here is some info from the Apple Support community about removing Mac Defender. 




Macintosh Flashback Virus


Apple has released a security patch for this virus. If you are using OS X 10.6 or 10.7, make sure and install all available updates for your mac. The patch was released as an Apple update, so installing the update will take care of the virus.

  1. What is the Flashback Virus?
  2. What about the new Flashback variant?
  3. How do I remove the virus if it is on my Mac?
  4. How can I protect my Mac from this and other possible infections?
  5. I'm not sure what my OS is, will this fix work for me? (10.5 users click here)


What is the Flashback Virus?

The Flashback virus targets a security hole in the Java software installed on your computer. Java is included with OSX, the operating system on your Mac. The virus is designed to steal personal information in the background without the user noticing, so once your computer is infected, you may not see any difference in the way it runs. To find out if your computer is infected, read the section below.


What about the new Flashback variant?

A new variant of the flashback virus has become available. In order to check if your device has this new variant you will need to open a terminal window by either searching for it using the Finder, or by opening Applications->Utilities->Terminal, then typing the following commands:

  • cd /Users/Shared
  • ls -al

You will be looking for any files ending in the extension ".so". There is a pending list of possible files that may be listed in that directory, so far they are:


There are several other files that may be there, their names and locations are as follows:

  • /Users/Shared/.svcdmp
  • ~/.MACOSX/environment.plist
  • ~/Library/Logs/vmLog

For removal instructions, read the information below:


How do I remove the virus if it is on my Mac?

Apple has released a software update that should fix the most common variants of the infection: directions on downloading that update are provided below:

  • Click on the Apple drop down menu in the upper left corner of the screen, and select "Software Update..."
  • Allow the machine to check for updates. There will be an update named Java Update for OS X 2012-003". Install the update!
  • Keep in mind this only covers the most common variants: there are some instances of this virus that won't be fixed by this update. Install ClamXAV if you haven't already, or some type of antivirus protection!

If you do not have ClamXAV installed, you can download and install it from their website.

PLEASE NOTE: The removal process involves running scans and possibly installing programs on your Mac. If you are not comfortable doing this on your own, you can get help on campus:

  • Students and Employees with personally owned computers:
    If you have a Macbook laptop, bring it to the Walk-Up Computer Helpdesk
    in the Valley Library. If you have a desktop, or you are unable to get to campus, you can call the OSU Computer Helpdesk for help over the phone.
  • Faculty with department issued computers:
    Contact your department support group for help


How can I protect my Mac from this and other possible infections?

There are several steps you can take to keep your Mac safe from infection.

Keep your Mac (and other programs) up-to-date

All viruses are designed to exploit security holes in different programs, and most updates work on patching these holes as they are discovered. Using out-of-date software makes it easier for infections to target your system.

To check your Mac for Apple updates:

  1. Click the Apple symbol in the upper-left hand corner of your screen
  2. Click the "Software Update" option. This will check for any Apple related updates. It will allow you to install if any updates are found.

To check your Mac for other program updates:

This varies based on what program you are using, but it can generally be found by opening the program, then looking for an "Updates" option in one of the top menus.

Updating your Operating System:

Older Mac Operating Systems (OSX) have additional vulnerabilities that newer versions don't have. The latest versions of Mac OSX are 10.7 and 10.6. You can check which version of OSX you are using by clicking the Apple symbol in the upper-left hand corner of your screen, and clicking on "About this Mac". If you have a version that is below 10.6, you may want to consider purchasing an upgrade for your computer if possible. Contact the OSU Computer Helpdesk for more details.


Install an Anti-Virus Program

Everyone is elligible to download free antivirus from ClamXAV. If you need help installing an Anti-Virus program, you can bring your Mac (If it is a laptop) to the Walk-Up Computer Helpdesk in the Valley Library. Note if you are faculty with a department owned Mac, you will need to contact your department support group for help.


Practice safe browsing habits when using the internet

Browsing to the wrong website is one of the most common forms of infection. Follow the suggestions on the safe browsing page for safe browsing tips.


I'm not sure what OS I use, what fix should I try?

Currently, 10.5 users and earlier are going to have to disable their Java until they can remove the infection, as the new update from Apple doesn't cover their OS. If you're not sure on how to find your OS version, follow the directions below:

  1. From the Apple menu (apple symbol in upper left-hand corner), select "About This Mac".
  2. The resulting window shows your operating system version.
  3. IF you have OSX 10.5 or lower, please use the following directions:
    • Click the Search button in the upper right hand corner, and type in “Java
    • Java Preferences should be the first item that comes up, click on it.
    • On the menu that comes up, uncheck all the boxes. This will disable Java for you.

PLEASE NOTE: If you are using OSX 10.5 or earlier, we highly recommend (for security reasons) that you look into purchasing an update if your computer supports it. If you have questions about updating, contact the OSU Computer Helpdesk.

If you are faculty and using a department issued laptop, you should be eligible for an upgrade through your department. Contact your department support group for help.