February 12, 2009

Has your PC become a spammer’s botnet zombie?


Scott Dunn By Scott Dunn

Worldwide spam traffic dramatically dropped after a major spam server was temporarily shut down last fall, raising public awareness of botnets: networks of PCs that have been turned into spam-spewing robots.

Most antivirus applications are ill-equipped to stop this kind of malware, but you can reduce the risk of having your PC become zombified.

Last November, a provider of Internet connectivity named Hurricane Electric pulled the plug on hosting company McColo. Immediately, the worldwide volume of spam dropped a whopping 65%, according to some estimates.

As explained by Brian Krebs in an cialis jelly title=”http://windowssecrets.com/links/casamqr63t9zd/948e29h/?url=www.washingtonpost.com%2Fwp-dyn%2Fcontent%2Farticle%2F2008%2F11%2F12%2FAR2008111200658.html%3Fsid%3DST2008111801165%26s_pos%3D”>article at WashingtonPost.com, Hurricane — one of the two companies McColo depended on for its Internet connection — took the action after the newspaper informed the provider of McColo's role in hosting all sorts of Internet bad guys.

According to Krebs, McColo's clients included "international firms and syndicates that are involved in everything from the remote management of millions of compromised computers to the sale of counterfeit pharmaceuticals and designer goods, fake security products, and child pornography via e-mail."

The spam reduction held for a couple of weeks before rebounding, according to a Nov. 26 story at InfoWorld.com.

McColo's servers didn't send out the spam themselves. Instead, they provided the command and control for a vast network of PCs infected with malware. A collection of hacked PCs that have been turned into automated spamming machines is known as a robot network or "botnet." Security professionals name these botnets after the malware that runs them, which include Asprox, Rustock, Cutwail, and Srizbil.

The malware creators rent their botnets to spammers, who in turn use the control servers to coordinate the transmission of huge amounts of junk mail, as explained in another Washington Post story.

Your computer could be a spam zombie and you might never know it. And if you think your security software is keeping your computer safe from botnet slavery, you'd better think again.

A recent study by security firm FireEye revealed that antivirus products detect bots less than half the time. The study tested AV programs using Virus Total's free malware-scan service; consult that site for a list of the AV products tested.

Your four-step spambot-safety program

What can you do to prevent becoming a botnet victim? Although there are no perfect solutions, the following actions will help prevent your system from being compromised. (My thanks to the security blog written by Wiz Feinberg for many of the tips.)

Step 1: Keep your security products up-to-date. Although the FireEye study found little protection against bots from antivirus products, the study's author, FireEye chief scientist Stuart Staniford, did note that "AV works better and better on old stuff — by the time something has been out for a couple of months, and is still in use, it's likely that 70% to 80% of products will detect it."

Update your antivirus program regularly with the latest patches and virus definitions; even if the app doesn't catch the latest bot, your AV protection will reduce your risk of catching older malware still circulating around the Internet.

Step 2: Use a software firewall. By carefully monitoring your Internet connection, you'll reduce your risk of infection by botnet malware. By default, the firewalls built into Windows XP and Vista monitor only incoming connections. The firewalls can be configured to monitor outbound traffic, but doing so is technical and problematic for most users. The differences between the firewalls in XP and Vista are described in this Microsoft TechNet article.

Many free, third-party software firewalls are bidirectional. Third-party firewalls sometimes require updates after you install Patch Tuesday fixes from Microsoft, but the added functionality of these firewalls can make this inconvenience worth living with. WS senior editor Ian "Gizmo" Richards describes the best products in his July 31, 2008, column.

Step 3: Get a free diagnosis. Some security products are intended specifically to combat the botnet plague. For example, RUBotted is a free utility from Trend Micro that sits quietly in your system tray and monitors suspicious activity (more info). If the program spots an infection, it alerts you to take action. The program is currently a beta, but it worked fine for me.

According to a post by security blogger Feinberg, RUBotted encourages you to scan your system with Trend Micro's free HouseCall online virus-scanning service, which detects and removes many malware infections. Note that on my system, RUBotted uses 8MB of RAM.

Trend Micro RUBotted
Figure 1. Scan your system with Trend Micro's RUBotted to ensure that your PC is bot-free.

Full disclosure: Feinberg's blog is sponsored in part by RUBotted's manufacturer, Trend Micro. But I don't consider this to be an argument against using RUBotted.

Step 4: Try Norton AntiBot. Another bot-specific security product is Symantec's Norton AntiBot (more info). This $30 program claims to monitor, detect, and remove bots before they can cause harm. Norton AntiBot uses behavioral analysis rather than definitions for specific bots and received an Editor's Choice award from PC Magazine in 2007.

Security sites such as Marshal continue to report spam-bot activity. The buggers are delivering junk mail, malware, and other odious data to millions of victims. By using the above bot-prevention tools and techniques, you'll reduce the chances that your machine's a spammer's helper.

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XP deadline extended toward launch of Windows 7

Dennis O'Reilly By Dennis O'Reilly

Microsoft has acknowledged that it will allow system builders to pay for installed copies of XP through May 30, rather than shutting down the pipeline this month.

If you order from your preferred vendor by Jan. 31, you may be able to rely on XP for new systems almost right up until the long-awaited Windows 7 ships, an event that's expected cialis instructions to occur within a few months.

Vista is looking more and more like the Edsel of the computer industry. Presumably as a result of slow uptake by corporations and individual users, Microsoft last month confirmed that it will allow OEMs and smaller-scale "system builders" to pay as late as May 30, 2009, for copies of XP ordered by Jan. 31. (Vendors won't have to pay Microsoft until the systems sell. MS previously had been expecting payments for copies of XP by Jan. 31.)

The details of Microsoft's new, flexible inventory program were first reported on the ChannelWeb site.

Combine this news with reports that Windows 7 may ship as early as mid-2009, and it looks like Microsoft is ready to relegate Vista to the binary scrapheap. Maybe the company's recent $300 million marketing push for Vista wasn't so successful as Microsoft claims it was.

As Mary Jo Foley states in her All About Microsoft blog, vendors of low-budget PCs such as netbooks were already being allowed to sell new systems based on XP through June 30, 2010, or one year after Windows 7 ships — whichever came first. Microsoft's new policy now gives a reprieve to builders of mainstream computers, and to end users who want to buy systems running Windows XP, not Vista, indefinitely or until Windows 7 is a proven commodity.

Will the Windows 7 RTM make an early entrance?

The official release of Beta 1 of Windows 7 to the public is widely expected to occur next week. If all goes well with the remaining testing, indications are that the final, RTM (released to manufacturing) version will be available as early as August. Lending support to this theory is the fact that the end-user license agreement of Beta 1, like all recent prerelease versions of Windows 7, states that the software will expire Aug. 1, 2009.

This feature — as well as the use of the product's built-in slmgr -rearm command to extend the beta's trial period without an activation key — was recently explained by Marius Oiaga of Softpedia. Other sources predict that Windows 7 won't ship to OEMs until October 2009, becoming available to end users the following month.

Early reviews of the Windows 7 beta, such as those summarized by the Telegraph of London, variously describe the new operating system as being not much different from Vista or representing an unspectacular-but-solid improvement. If Windows 7 turns out to have better performance and reliability than Vista, as some reviewers believe, the OS may gain a measure of relieved acceptance from end users after only a few months on the market.

Paying a premium to downgrade from Vista to XP

The extended availability of XP on new PCs will gladden the hearts of many Windows users. For a few unfortunates, however, the XP option is coming at great cost.

Eric Krangel reports on the Silicon Alley Insider blog that Dell has gradually been inflating its surcharge for "downgrading" a PC from Vista to XP. The bite rose last June from U.S. $20 to $50, then spiked in October to $100, and now is a whopping $150.

The fact that Dell's customers appear to be willing to pay this amount or more to avoid Vista may be the greatest indictment of Microsoft's unloved OS.

The reality is that the Redmond software giant has been forced by popular opinion to provide customers with a Vista-free option — an extended life for XP — more than two years after Vista's rollout. Depending on your point of view, this concession can be interpreted negatively as an act of desperation or more positively as a burst of marketing acumen on the company's part.

As usual, the truth is likely somewhere in between.

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Access more memory, even on a 32-bit system

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Scott Dunn By Scott Dunn

No matter how much memory you have in your PC, you may not be getting the most out of your installed RAM.

A few little-known system tweaks can improve the way Windows manages memory, freeing up more RAM for your applications.

As described in an entry on the Microsoft Developer Network, all non-server 32-bit versions of Windows XP and Vista impose a memory limit of 4GB. Your system may allow you to install more than this amount of RAM, but with few exceptions, the extra memory won't do Windows or your applications any good.

Moreover, even if you have 4GB of memory installed in your PC, you may not be able to use it all. For example, if your video card comes with 1MB of memory and you have 4GB of RAM, your system actually has 5GB of memory physically installed. But Windows will use only 4GB of that total, regardless.

It gets worse: according to a comment posted to the MSDN article, Windows itself is getting only 3GB because the video card gets 1GB. This happens because the memory aperture — a portion of system memory — is used to work with the video system.

Ways to break through Windows' RAM ceiling

Fortunately, there are techniques you can use to get around Windows' system-memory limitations. One method is to use Physical Address Extension (PAE), a feature of x86 processors that lets 32-bit operating systems overcome the 4GB memory limit.

Another MSDN article explains that 32-bit Windows operating systems support PAE. Even though XP and Vista still cling to the 4GB limit with PAE enabled, the feature may help you get back some of your unused RAM.

In one or two rare cases, a developer may take advantage of PAE technology to get around the usual Windows limits. For example, reader Alan Gorski reports that when he increased a computer to 8GB, the program AutoCAD was able to open large drawing files without generating the "out of memory" errors he previously had seen. As Gorski notes, "AutoCAD has long used special memory management techniques since the DOS days to maximize use of available RAM."

There's a good chance your system is already using PAE. That's because Windows relies on the technology to support the security feature known as Data Execution Prevention (DEP). For more information about Windows and DEP, see my Top Story in the May 3, 2007, issue.

If a computer supports hardware-enforced DEP, then PAE is enabled as well. Here's how to check for it in Windows XP:

  • Step 1. Choose Start, Run.
  • Step 2. Type sysdm.cpl and press Enter.
  • Step 3. Click the Advanced tab. In the Performance box, click Settings and choose the Data Execution Prevention tab.
  • Step 4. Look for a status message at the bottom of the dialog box. If it indicates that your hardware does not support DEP, chances are PAE is not enabled.

To check your system's PAE status in Vista, do the following:

  • Step 1. Press Win+R to open the Run dialog box.
  • Step 2. Type SystemPropertiesDataExecutionPrevention and press Enter.
  • Step 3. If prompted by User Account Control, click Continue.
  • Step 4. If the status message at the bottom of the dialog box says your system supports DEP and the "Turn on" button is selected, then PAE is enabled as well.

If PAE is not already enabled on your system, here's how to activate it in Windows XP:

  • Step 1. Choose Start, Run.
  • Step 2. Type notepad c:\boot.ini and press Enter.
  • Step 3. Under the [operating systems] heading, look for a line that contains the /noexecute switch, which turns software DEP. For example, it may be /noexecute=optin, /noexecute=optout, or /noexecute=always on. Place the cursor directly after that switch and type a space followed by /pae. Save the file and reboot.

If you don't have DEP enabled on Vista (or you don't want it enabled), you can still activate PAE by following these steps:

  • Step 1. Click Start, type cmd.exe and press Ctrl+Shift+Enter.
  • Step 2. If prompted by User Account Control, click Continue. This opens a command prompt window with administrator privileges.
  • Step 3. At the prompt, type BCDEdit /set PAE ForceEnable and press Enter.

You can read more about PAE in this post on Microsoft's TechNet site.

Microsoft warns in another TechNet article that some drivers will not load if PAE is enabled. After you make this change, keep an eye on your system. If you have problems with drivers or your system starts acting up, remove the /pae switch from boot.ini in XP, or enter the following command line in an administrator command prompt in Vista:

BCDEdit /set PAE ForceDisable

For more information on the switches and settings related to PAE, consult this MSDN paper, "Boot Parameters to Configure DEP and PAE."

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Does the glitch in .NET patching put you at risk?

Susan Bradley By Susan Bradley

People using Windows XP Service Pack 3 may not be offered all the .NET security patches their applications require.

However, if none of your PC's programs requires a version of .NET Framework, this problem will have no impact on your system.

My Dec. 4 cialis how it works title=”http://windowssecrets.com/links/casamqr63t9zd/a9dbach/?url=www.windowssecrets.com%2F2008%2F12%2F04%2F03-XP-Service-Pack-3-blocks-.NET-security-patches”>Top Story stated that, due to a bug, Windows XP SP3 users aren't being offered security patches for Microsoft's .NET Framework 3.0. I'm publishing this special column today because several of you asked whether your XP SP3 systems are at risk as a result of this glitch.

First I'll give you some background on .NET Framework, and then I'll describe how to tell whether you need to be concerned about the matter.

Microsoft created .NET Framework to provide building blocks for applications. .NET is not a component of Windows itself. I strongly recommend that you avoid downloading .NET until you install an application that requires one, at which time the program will likely install the necessary version for you.

To determine whether you have any versions of .NET Framework installed on an XP PC, open the Add or Remove Programs applet in Control Panel and look for entries reading Microsoft .NET Framework. If you don't see any such entries, you needn't worry about the update failure.

If you do see .NET Framework in the list of currently installed programs, you need to make sure you're receiving all the updates your system requires.

When you open the Microsoft Update service on Windows XP, you'll see buttons labeled Express and Custom on the Welcome screen. Click Custom to see three patching categories under Select by Type in the left pane: High Priority; Software, Optional; and Hardware, Optional.

Microsoft Update's list of optional updates
Figure 1. Clicking the Custom button on Microsoft Update's Welcome screen shows a list of high-priority and optional updates for your PC.

While all three categories can be considered security-related, in reality only the top section lists critical patches. The second section shows optional patches for Windows and your apps; the third lists driver updates.

Always install patches listed in the upper section. You can selectively install patches from the Software, Optional section, but I recommend that you never install driver updates directly from the bottom section. In the past, drivers I've downloaded from Microsoft's update service have caused problems. Instead, go to the vendor's own site and download driver updates from there. And remember: if the device isn't causing any problems, refreshing its driver software may be more trouble than it's worth.

When I tested several XP SP3 systems, the upper section of the update window — which lists critical security patches — looked much the same as it did on XP SP2 machines. However, SP2 and SP3 showed many differences in the middle section listing optional software updates, including those for .NET Framework.

There's a very good reason the updates in the middle section are listed as "optional." Until an application on your system requires .NET Framework to function, don't install any .NET Framework patches.

Microsoft's update service will offer systems running XP SP2 an update to .NET Framework 3.0, but machines using XP SP3 won't see it listed among the optional patches.

Because of this difference — and the fact that .NET installs can fail, as I discussed last week — I urge you to regularly use a third-party software-update service such as Secunia's free online Software Inspector or the company's standalone program, Personal Software Inspector (obtain PSI from its download page), to check the vulnerability of your PC's software.

PSI scans for outdated and vulnerable versions of Sun's Java, Apple's QuickTime, Adobe's Flash and Acrobat, and other common programs that put your system and data at risk if they're not patched. After scanning 20,000 machines in a recent seven-day period, Secunia reported on Dec. 2 that fewer than 2% of the computers were fully patched.

By the way, several readers notified me that they had problems with the Secunia software scanner. I'll investigate these issues and report what I find in a future Patch Watch column.

Here's the bottom line: don't install any .NET Framework patches listed in Microsoft Update's "Software, Optional" section unless you're sure you have the corresponding .NET Framework installed on your system. Any application requiring a specific .NET Framework, such as Intuit's Quickbooks accounting program, will install the necessary version automatically.

Once the Framework is on your machine, install any offered security patches for it, but be prepared for potential installation glitches. Aaron Stebner's .NET Framework cleanup tool (download page) can help you out if a .NET update gets stuck. You may have to uninstall that version of .NET and reinstall it, as described by Alan Crawford in this week's Known Issues column.

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A manual approach to reinstalling .NET Framework

Dennis O'Reilly By Dennis O'Reilly

The Dec. 4 Top Story in Windows Secrets described how to make sure your system has the Microsoft .NET that's needed by various applications, but doing so sometimes requires a brute-force approach.

When it's time to reinstall vital Windows components — or the entire operating system — you'd best have a plan in mind.

That's what reader Alan Crawford found out after stumbling through a reinstallation of Windows XP on one of his PCs:

  • "I recently had to reinstall a PC that uses a handful of .NET apps. After installing Windows [XP] from an SP2 image, I used Microsoft Update to reinstall all necessary patches and updates, including the three .NET versions and their various service packs and other patches. Having already encountered problems with .NET patches on other machines, I wasn't surprised when .NET 1.1 SP1 wouldn't install.

    "In the past, I was able to uninstall all .NET versions and then proceed, one at a time, to get them all reinstalled. No such luck this time. After several rounds and many visits to the Microsoft Knowledge Base — even using the .NET cleanup tool — I still could not get this package to install.

    "My last-gasp effort was to try the whole exercise 'manually,' and it worked! Despite the extra time involved — and having to validate the PC on each download — had I started on this tack to begin with, I would have saved hours of frustration (seemed like hours, anyway, even if it wasn't).

    "Here's the procedure I used:

    • Step 1: I had previously downloaded the .NET cleanup tool.

    • Step 2: I removed all traces of existing .NET installations and then ran the .NET cleanup tool.

    • Step 3: I rebooted.

    • Step 4: I manually downloaded .NET 1.1, 1.1 SP1, 1.1 SP1 Hotfix, and 2.0 installers — individually — from the Microsoft download site.

    • Step 5: I installed them in the order downloaded, with reboots as required.

    I picked up at this point with downloads from Microsoft Update — installing the 2.0 Hotfix, then 3.0, then the 3.0 Hotfix in separate runs — and all now seems to be just fine.

    "Thanks, as always, for the best newsletter out there."

Free option for controlling kids' Net access

Becky Waring's Dec. 4 parental-control software review (paid content) led reader Rob de Santos to tell us about a new way to use an old, reliable — and free — Internet security service:

  • "I highly recommend an option usually overlooked by most parents (and unknown to them): control access via your router. If you utilize Open DNS and follow their instructions to change your router's DNS settings, you can then use the easy-to-configure OpenDNS settings pages to block any category of sites you choose, be it … porn, chat, or advertising.

    "This is an excellent supplement to any PC-based software and much harder for any child to override or avoid. It can also be remotely changed if necessary. Best of all, it's free!"

Free is good. Difficult for a clever child to overcome is even better. And I know a lot of Internet users who'd be interested in a free, effective way to block Web ads.

Note that in her July 24, 2008, Patch Watch column (paid content), Susan Bradley described how to use the OpenDNS forwarding service to improve the security of routers and Web servers.

Speaking of Susan, since her lead story about problems patching Microsoft's .NET Framework appeared on cialis herbal alternative color=”#000099″>Dec. 4, she's dug up additional information. Although she usually writes for Windows Secrets' paid content, her follow-up on .NET appears today as a free column.

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