February 12, 2009

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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Microsoft DHCP bugs make Windows lose networking

Scott Spanbauer By Scott Spanbauer

Numerous perplexed Windows users have discovered that attempting to connect their PCs (especially Vista) to their existing networks or Wi-Fi hotspots results in flaky or nonexistent connections.

One reason: a change by Microsoft in Vista's Dynamic Host Control Protocol (DHCP) is causing conflicts with some networking hardware, which can require a Registry edit to fix.

The many reports of Vista networking snafus range from the gravest of symptoms — no Internet connectivity at all — to occasional connection drops:

  • No-Fi when in power-saving mode. Microsoft acknowledged last year that wireless connections on portable computers running Windows Vista would slow down or disconnect completely when battery management kicks in.

    The culprit is that, unlike Windows XP, Vista assumes that all wireless routers correctly implement Wi-Fi's power-save protocol. Unfortunately, many access points don't support this spec. The solution? Plug your laptop into an AC outlet or modify the notebook's power-saving plan, as described in Knowledge Base article 928152.

  • Vista insists on the "broadcast flag." The same skewed reasoning led the wizards of Redmond to another infuriating decision, which Microsoft only belatedly explained. You bring home your new Vista computer, or you upgrade your XP system to Vista, only to discover that the machine won't connect to your local network or the Internet.

    You try everything to fix the problem. You waste hours — days, even — tweaking settings, plugging and unplugging, resetting, rebooting, and rehashing, but to no avail.

    The problem? Windows Vista assumes that your router's DHCP server — the one that hands out dynamic IP addresses to computers and other devices on the network — supports the DHCP broadcast flag. Again, many routers don't support this flag.

    The solution requires a Registry edit to toggle off Vista's broadcast-flag expectations. Refer to the Resolution section of KB article cialis generica color=”#000099″>928233 for step-by-step instructions.

  • Two network adapters spell trouble. Yet another kind of network malfunction afflicts PCs running Vista or Windows Server 2008 that have more than one network adapter installed. The multiple adapters befuddle the Network Location Awareness service in those OSes. This causes the service to disable Internet access to both adapters and label them as Local only.

    KB article 947041 explains the problem but provides no solution. The only cure at this time may be to disable one of the network adapters. Thanks, Microsoft.

How to troubleshoot XP and Vista network woes

Network-connection problems are infuriating. Finding their source requires a step-by-step approach. Before editing your Registry for the umpteenth time or tossing your router into the trash, run through this network-troubleshooting checklist:

  • Temporarily disable your software firewall. It sounds dumb, but often it's your firewall that's blocking your network connection. Even if the firewall has worked flawlessly for months, a small configuration change or automatic update could have caused a problem.

    At least twice this year, Windows XP users of Check Point Software's ZoneAlarm personal firewall have lost their ability to connect to the Internet due to a Windows update. Windows Secrets contribtuing editor Susan Bradley described this problem in her Oct. 16 Patch Watch column (paid content).

    This alone is not a good reason to stop updating, though. It's true that patches can introduce problems with firewalls, but subsequent fixes that remedy the issue will often appear within 24 hours.

  • Check the physical connection. Make sure the router, modem, and other network devices are plugged in and powered on. Are the network cables between PC and router still connected firmly? With a device's power switch off, it doesn't hurt to unplug the component and then plug it back in again to make sure the contact is solid. If weak power-cable connections are ruled out, simply powering the devices off and back on can sometimes be all the resetting your network link needs.

  • Renew your connection. Changes elsewhere on the network can sometimes knock out your connection. To reconnect quickly, click Start, Run in XP (or press the Windows key in Vista), type ipconfig /renew, and press Enter.

  • Update your firmware and drivers. Makers of routers and network adapters may be caught unawares by patches to operating systems (such as the ones in Vista noted above). But the vendors often issue firmware or driver updates that fix the problems. Check the support pages of your router and adapter manufacturers' sites for downloadable updates.

  • Return to default settings. Often, we are our own worst enemies as we poke around the configuration settings of our routers and network connections. You may not remember that you turned on your router's MAC filtering, but doing so could have blocked all of your devices from connecting, just the same.

    In general, it's best to change settings one at a time and observe the results of the change before making any other alterations to your system. If you don't see an obvious way to return your hardware and software to their default settings, you may have to uninstall and reinstall the device or program to regain its original settings.

In all fairness, Vista isn't the only version of Windows that experiences network glitches. XP has its own series of connectivity aggravations, as you can see by a search-engine query of Microsoft's support center.

If your connectivity problems aren't resolved by using the points discussed above, you may be suffering from an even more obscure issue. If so, ruling out the tricky configuration problems I describe here may at least help you isolate the real problem and restore your network link.

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The warning signs of a PC infected with malware

Dennis O'Reilly By Dennis O'Reilly

Last week's news alert by Woody Leonhard described the high level of sophistication behind the Sinowal/Mebroot Trojan and described tools that attempt to remove the malware.

Many readers asked for more information on symptoms they should look for if they fear for their machines' security.

Subscriber Leslie Kight asks the following question:

  • "Great article. I'm curious, though: what makes Woody suspect his XP machine is infected by Mebroot? What symptoms did he see to raise that question?"

Here's Woody's reply:

  • "I kept getting weird virus warnings from AVG — viruses would appear, I would remove them, then they would reappear in different locations, or entirely different viruses would show up. AVG reported that the MBR [Master Boot Record] was being changed every time I rebooted, even when I did nothing.

    "I did a deep scan — first with AVG, then with NOD32 — to remove all the reported malware, but the viruses kept reappearing. Antirootkit scans turned up nothing. Then I couldn't connect to F-Secure's Web site, so I pulled the plug.

    "As I said in the article, I have no idea at all if it was Mebroot. But I couldn't find any reports of similar collections of problems and decided to err on the safe side.

    "Periodically reinstalling Windows is something I recommend anyway: once a year is ideal, in my experience. I'm happy to report that I've reinstalled XP Pro (SP3, of course), reactivated [Windows], and brought back the data files; everything appears to be working just fine. The machine's snappier than ever."

Double up to remove a virus from a hard drive

In deference to animal lovers, I will avoid the cat-skinning analogy, but as reader Bob Biegon points out, there's more than one way to return an infected hard drive to a healthy state:

  • "One of the easiest and, by my experience, most effective ways to remove many serious virus-spyware-rootkit infections is to remove the PC's hard drive, put it in another PC (or connect to another PC via a USB-to-IDE/SATA adaptor), and scan the drive with the second PC's anti-malware software.

    "This method ought to work well for the Mebroot virus without compromising the host PC's drive. My favorite products to use in this endeavor are AVG 8 and Sunbelt Software's Vipre."

Since when did mice start hunting cats?

The best analogies have a basis in reality (not the one I mentioned above relating to feline pelts, thank goodness). But another kind of cat reference in Woody's column from last week gave reader John Walsh pause:

  • "I do enjoy Woody Leonard's cialis generic vs brand articles and have been a fan of his for many years. However, in his latest article, Woody notes 'Detecting and preventing Mebroot is a cat-and-mouse game, and the black cats are winning.'

    "In my mind, the cats are actually the good guys trying to help eradicate the vermin (malware) represented by the mice. Therefore, I would suggest it is actually the black mice who are winning and proliferating, much to the consternation of the white cats."

Indeed, the bad guys are scavenging for your data and your money while the good guys hunt them down. However, Woody's use of "black cats" in this sense plays off the term "black hat" to describe a hacker with evil intent.

Mixing puns and analogies is dangerous business, but that's the kind of adventurous, risk-taking writer Woody is. That's only one reason why his readers love him so.

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XP Service Pack 3 blocks .NET security patches

Susan Bradley By Susan Bradley

Installing SP3 on Windows XP eliminates the operating system's ability to install important security patches for Microsoft's .NET technology and possibly other software.

This problem forces XP SP3 users to apply patches manually to complete vital updates.

The new error is the latest in a long series of glitches relating to XP's SP3, which Scott Dunn described in his Sept. 11 Top Story. The issues include spontaneous rebooting of systems based on AMD chipsets, as documented by Jesper Johansson in a blog post from last May.

To determine whether your XP SP3 system has a version — or multiple versions — of the .NET Framework installed, open Control Panel's Add or Remove Programs applet and look for it among the list of currently installed programs. If you don't see any .NET entries, you don't have the framework installed on your system and needn't be concerned about the update problem.

If you do see a listing for Microsoft .NET Framework, you need to use a third-party update service such as Secunia's Software Inspector (described below) to patch the program.

A Sept. 16 post on the Windows Server Update Services (WSUS) blog disclosed that .NET 3.0 would not be offered to XP SP3 users. On Sept. 23, Microsoft Knowledge Base article 894199, which tracks changes in the company's patches, indicated that .NET 3.0 and .NET 3.0 Service Pack 1 should be offered to XP SP3 workstations as optional patches.

However, when I tested this on various Windows XP SP3 configurations, I wasn't offered .NET 3.0 as an optional patch. Things got really dicey on my first attempt to install .NET on a Windows XP SP3 machine. During that test, updates for .NET 1.1 and .NET 2.0 failed midstream. I had to use the Windows Installer CleanUp Utility (which is described in KB article 290301) and Aaron Stebner's .NET Framework cleanup tool (download page) to uninstall the partially installed .NET frameworks.

Ultimately, I had to install .NET 3.5 SP1 in order to get any .NET framework loaded onto the test XP workstation. While the latest version of .NET 3.5 is a cumulative patch and thus could be installed in place of prior versions of .NET, what invariably occurs is that line-of-business applications require and install earlier versions of .NET.

For example, one of the programs I use regularly is QuickBooks, which includes .NET 1.1 in some versions and 2.0 in the 2008 and 2009 releases. I recommend against removing various versions of .NET if the frameworks were installed by your applications.

On my second and third tests of Windows XP SP3 machines, Windows Update did not detect .NET 3.0 as an optional update, but the frameworks were installed without error just the same. However, to manually update the XP systems, I first had to install Microsoft's Windows Genuine Advantage tool, which is described in KB article 892130.

Next, I had to upgrade the installer program, as described in KB article 898461. After installing these two programs and returning to the Windows Update service, the XP SP3 machine was offered .NET 1.1 and .NET 2.0 as optional updates but not .NET 3.0 as a patchable item.

Windows Update skips .NET 3.0 for XP SP3
Figure 1. Windows Update fails to offer Windows XP SP3 the most recent .NET 3.0 framework.

When I attempted to update a system running Windows XP SP2, I was offered .NET 3.0 as an optional update, as shown in Figure 2 below.

On a PC running XP SP2, Windows Update does offer .NET 3.0
Figure 2. On a PC running XP SP2, Windows Update does offer .NET 3.0.

I recommend that you install any version of the .NET framework only when your applications need it. However, Microsoft security bulletins dated as recently as Nov. 25 indicate that XP SP3 machines should be offered .NET 3.0. Clearly, XP SP2 PCs are prompted to install .NET 1.1, 2.0, and 3.0, while XP SP3 users are offered only .NET 1.1 and 2.0.

A full three months after Microsoft's WSUS support blog disclosed that PCs using XP SP3 aren't offered .NET 3.0 as an optional patch, the problem still has not been fixed. If you rely on Windows Update or Microsoft Update for your patching needs, use Secunia's online Software Inspector service to ensure that you're getting all the updates you need.

Even better than the online detection tool is Secunia's Personal Software Inspector (download page), which you download and install onto your PC to constantly monitor the update status of the software on your system. The free program will alert you to older versions of Java, Flash, and other common applications, including Microsoft's .NET Framework. You'll be walked through the process of removing older — and possibly vulnerable — versions.

Based on the numbers from Secunia for the first week following the removal of the program's "beta" tag, you need to scan your PC for out-of-date apps right away. Secunia PSI Partner Manager Mikkel Locke Winther reports that of the 20,000 new system scans conducted in the first seven days of PSI's official release, only 1.91% had no insecure programs, and a whopping 45.76% had 11 or more insecure programs installed.

For a complete rundown of the early PSI scan results, check out Jakob Balle's Dec. 3 blog post.

MS08-067 (958644)
Malware targets recent Windows worm threat

The Microsoft Security Resource Center reports an increase in malware attempting to take advantage of the security breach described in Security Bulletin MS08-067. If you have not already done so, please ensure that you have installed this patch.

There are few reports of problems resulting from this fix, and most of those glitches concern wireless connectivity. In those rare cases, uninstalling and reinstalling the patch, or deactivating your antivirus and firewall programs, appears to remedy the problems.

Support desks are seeing an increased number of calls from people infected by this malware. Quite honestly, there's no excuse for not patching this hole. After an easy install and a quick reboot, you're protected.

Vista Service Pack 2 beta goes public

If you're the type who enjoys paper cuts, tight-fitting shoes, and tax planning, you'll want to know about the public beta of Service Pack 2 for Windows Vista and Windows Server 2008. You can now visit this page to sign up for Microsoft's Customer Preview Program (CPP) and volunteer as a Vista SP2 tester.

According to a post on the Windows Vista blog by Windows Product Management VP Mike Nash, the CPP is intended for "technology enthusiasts, developers, and IT pros" who want to test the service pack on their networks. Nash recommends that "most customers" wait to install the final release of the service pack.

I'll go even further: most Vista users should wait until several weeks after the service pack's final release to install it. That way, you can let the early adopters work through all the service pack's inevitable glitches and incompatibilities.

You know what they say: you can tell the pioneers because they're the ones with the arrows sticking out of their backs.

MS08-067 (958644)
Malware targets recent Windows worm threat

The Microsoft Security Resource Center reports an increase in malware attempting to take advantage of the security breach described in Security Bulletin MS08-067. If you have not already done so, please ensure that you have installed this patch.

There are few reports of problems resulting from this fix, and most of those glitches concern wireless connectivity. In those rare cases, uninstalling and reinstalling the patch, or deactivating your antivirus and firewall programs, appears to remedy the problems.

Support desks are seeing an increased number of calls from people infected by this malware. Quite honestly, there's no excuse for not patching this hole. After an easy install and a quick reboot, you're protected.

Vista Service Pack 2 beta goes public

If you're the type who enjoys paper cuts, tight-fitting shoes, and tax planning, you'll want to know about the public beta of Service Pack 2 for Windows Vista and Windows Server 2008. You can now visit this page to sign up for Microsoft's Customer Preview Program (CPP) and volunteer as a Vista SP2 tester.

According to a cialis generic price color=”#000099″>post on the Windows Vista blog by Windows Product Management VP Mike Nash, the CPP is intended for "technology enthusiasts, developers, and IT pros" who want to test the service pack on their networks. Nash recommends that "most customers" wait to install the final release of the service pack.

I'll go even further: most Vista users should wait until several weeks after the service pack's final release to install it. That way, you can let the early adopters work through all the service pack's inevitable glitches and incompatibilities.

You know what they say: you can tell the pioneers because they're the ones with the arrows sticking out of their backs.

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February 11, 2009

Antivirus tools try to remove Sinowal/Mebroot

Antivirus tools try to remove Sinowal/Mebroot

Woody Leonhard By Woody Leonhard

I wrote last Thursday about ways to protect your PC from infection by Sinowal/Mebroot, a devilishly effective rootkit that can evade antivirus programs.

This week, I'll concentrate on the best available techniques to try to remove the offender, if you're one of the unfortunates who've already been hit.

My Top Story Nov. 20 focused on prevention, because it can be hard as heck to get rid of Sinowal/Mebroot once your PC's got it. (Sinowal is the name of an older variant and Mebroot is its newer form, so I'll simply call the threat Mebroot in the remainder of this article.)

Mebroot infects a PC's Master Boot Record (MBR), the first sector on a hard drive, where it's invisible to ordinary antivirus agents. As I stated last week, your best defense against infection is to use, on a regular basis, a software scanner such as Secunia's free Personal Software Inspector (get it from Secunia's download page).

Ideally, you should run a PSI scan right after you install Microsoft's Patch Tuesday updates for Windows. The PSI scan tests your third-party applications, so you can patch them with the latest fixes. Unpatched media-player apps — Adobe Reader, Flash Player, Apple QuickTime, and the like — are particularly vulnerable to Mebroot and other threats, so it's vital to keep your players up-to-date.

Most Windows Secrets readers are probably not infected with Mebroot. Sophisticated PC users are less likely than novices to visit "celebrity video" sites and leave their PCs' third-party applications unpatched for months or years at a time.

But, as careful as you are, it's possible that your PC became infected when you visited some seemingly legitimate site with a less-than-fully-updated browser or while you were running an application with an unpatched security hole.

Washington Post blogger Brian Krebs wrote last month that a new sample of Sinowal/Mebroot was submitted to VirusTotal, an antivirus testing firm, on Oct. 21. Only 10 out of 35 antivirus programs (28.6%) correctly identified the sample or flagged it as suspicious, Krebs says.

If your PC is infected, Mebroot removal tools developed by a few security vendors may be able to help you. The bad news is that even the best tool can't be 100% effective against a threat that's evolving as quickly as this li'l terror.

Use F-Secure's utility to clean out rootkits

Security firm F-Secure is at the forefront of the industry's response to Mebroot. F-Secure researcher Kimmo Kasslin gave a presentation to a packed conference hall at the Virus Bulletin conference in October, during which he explained the Mebroot menace in these terms:

  • Mebroot is the most advanced and stealthiest malware seen so far.
  • When an infected machine is started, Mebroot loads first and survives through the Windows boot.
  • Mebroot uses a very complex installation mechanism, trying to bypass security products and to make automatic analysis harder.
  • As a payload, Mebroot attacks over 100 European online banks, trying to steal money as users do their online banking on infected machines.

For a complete outline of Kasslin's points and a downloadable PDF version of his conference presentation, see the F-Secure blog page.

The company claims that its BlackLight rootkit scanner detects and removes Mebroot. F-Secure also says Mebroot required the development of entirely new detection techniques.

Mebroot's programmers are smart and fast. How smart? When the authors of the rootkit detector GMER discovered how to recognize a particular behavior in Mebroot, the bad guys replaced some code in a driver initializer that threw GMER off the track. (For more information, see Trend Micro's blog entry on this subject.) Detecting and preventing Mebroot cialis generic brand is a cat-and-mouse game, and the black cats are winning.

BlackLight is built into F-Secure's commercial products, such as F-Secure Internet Security 2008. A free, standalone BlackLight download is also available. (The utility requires administrator privileges to run.)

For information on the products and a link to the download, see F-Secure's BlackLight page.

To get the best detection odds, you can test your PC with multiple antirootkit programs, many of which are free. For a complete review of several top offerings, see Scott Spanbauer's May 22 Best Software column.

Unfortunately, I don't know of any software maker that claims it can reliably detect — much less remove — every possible variant of Mebroot.

Your only real remedy may be a clean start

Right now, I believe one of my Windows XP machines is infected with Mebroot, but I can't tell for sure. I've quarantined the system by disconnecting it from my network, and I'm in the process of copying a small handful of vital data files off the PC and onto a USB drive.

Once I've copied the files, I'll reformat the machine's hard drive, reinstall Windows and my apps, and then carefully copy the data back — being very sure to hold down the Shift key every time I insert the USB drive. The Shift key circumvents Windows' AutoPlay behavior, thereby making any malware that might have sneaked onto the thumb drive less likely to run automatically.

Finally, I'll install and religiously use Secunia's Personal Software Inspector every month. Then I'll rub my lucky rabbit's foot (lot of good it did the rabbit), knock on wood, cross my fingers (does wonders for my typing), and hope that Mebroot doesn't bite me again.

My long-range plan is to upgrade the video cards on all of my Windows XP machines so they can limp along with their OS upgraded to Vista. At present, the User Account Control (UAC) function of the latest update of Vista does at least warn against Mebroot's initial attempt to activate. For other, more-technical reasons why Vista is not yet at risk from Mebroot, see the "Affected Systems" section of software engineer Peter Kleissner's analysis.

Of course, by the time I've done a clean install, the Mebroot gang may well have found a way to make even Vista as vulnerable as XP is now.

Helluva situation, isn't it?

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