Category Archives: Security

aka infosec

Timeline: NSA hacking tool to WannaCry

A recent Washington Post article is helping to answer some questions about Microsoft’s actions in recent months. Here’s a timeline of events:

2012 (or possibly earlier): The NSA identifies a vulnerability in Windows that affects all existing versions of the operating system, and has the potential to allow almost unfettered access to affected systems. A software tool — an exploit — is developed either for, or by, the NSA. The tool is called EternalBlue. People at the NSA worry about the potential damage if the tool or the vulnerability became public knowledge. They decide not to tell anyone, not even Windows’ developer, Microsoft.

EternalBlue finds its way into the toolkit of an elite hacking outfit known as Equation Group. Although it’s difficult to know for certain, this group is generally assumed to be operating under the auspices of the NSA. Equation Group may work for the NSA as contractors, or they may simply be NSA employees. Regardless, the group’s actions seem to align with those of the NSA: their targets are generally in places like Iran, Russia, Pakistan, Afghanistan, India, Syria, and Mali.

Early to mid-2016: A hacking group calling themselves The Shadow Brokers somehow gains access to NSA systems or data, and obtains copies of various NSA documents and tools. Among those tools is EternalBlue.

August, 2016: The Shadow Brokers begin publishing their NSA haul on public services like Tumblr.

January 7, 2017: The Shadow Brokers begin selling tools that are related to EternalBlue.

Late January to early February 2017: The NSA finally tells Microsoft about the vulnerability exploited by EternalBlue. We don’t know exactly when this happened, but it clearly happened. The NSA was Microsoft’s source for this vulnerability.

February 14, 2017: Microsoft announces that February’s Patch Tuesday updates will be postponed. Their explanation is vague: “we discovered a last minute issue that could impact some customers.

Late February 2017: The Windows SMB vulnerability exploited by EternalBlue is identified publicly as CVE-2017-0144.

March 14, 2017: March’s Patch Tuesday updates from Microsoft include a fix for CVE-2017-0144, MS17-010. The update is flagged as Critical and described as Security Update for Microsoft Windows SMB Server (4013389). Nothing in Microsoft’s output on March 14 calls special attention to this update.

April 14, 2017: The Shadow Brokers release 300 megabytes of NSA material on Github, including EternalBlue.

May 12, 2017: WannaCry ransomware infection wave begins. The malware uses EternalBlue to infect vulnerable computers, mostly Windows 7 PCs in Europe and Asia. Infected computers clearly had not been updated since before March 14, and were therefore vulnerable to EternalBlue.


It’s now clear that the NSA is the real problem here. They had several opportunities to do the right thing, and failed every time, until it was too late. The NSA’s last chance to look at all good in this matter was after the vulnerability was made public, when they should have made the danger clear to the public, or at least to Microsoft. Because, after all, they knew exactly how useful EternalBlue would be in the hands of… just about anyone with bad intent.

Everyone involved in this mess acted foolishly. But whereas we’ve grown accustomed to corporations caring less about people than about money, government institutions — no matter how necessarily secretive — should not be allowed to get away with what the NSA has done. Especially when you consider that this is just the tip of the iceberg. For every WannaCry, there are probably a thousand other threats lurking out there, all thanks to the clowns at the NSA.

Ars Technica’s analysis.

Techdirt’s analysis.

WannaCry update

According to Kaspersky Labs, almost all of the computers infected with WannaCry (WCry, WannaCrypt) were running Windows 7. A small percentage (less than 1%) were running Windows XP.

Microsoft released updates in March 2017 which — if installed — protect Windows 7 computers from WannaCry infections. So all those Windows 7 WannaCry infections were only possible because users failed to install updates. This is a good argument for either enabling automatic updates, or being extremely diligent about installing updates as soon as they become available.

A researcher at Quarkslab discovered a method for decrypting files encrypted with WannaCry, although it only works on Windows XP, and only if the computer has not been restarted since the files were encrypted.

Building on the discoveries of Quarkslab, researchers at Comae Technologies and elsewhere developed a tool that can decrypt files encrypted by WannaCry on Windows 7 as well as XP. The new tool — dubbed wanakiwi by its developers — uses the same technique as its predecessor and has the same limitation: it doesn’t work if the infected computer has been restarted since encryption occurred.

The Register points out that while the NSA was hoarding exploits, Microsoft was doing something similar with patches. Microsoft is in fact still creating security updates for Windows XP and other ‘unsupported’ software; they just don’t normally make those updates available to the general public. Instead, they are only provided to enterprise customers, which pay substantial fees for the privilege. When Microsoft released the Windows XP patch in response to the WannaCry threat, the patch was already developed; all Microsoft had to do was make it available to the general public. Sure, developing updates costs money, and Microsoft wants to recover those costs somehow, but it seems clear that we would all be better off if they made all updates available to everyone.

Bruce Schneier provides a useful overview of WannaCry, and how best to protect yourself. From the article: “Criminals go where the money is, and cybercriminals are no exception. And right now, the money is in ransomware.”

Update 2017May21: Analysts have confirmed that WannaCry’s initial infections were accomplished by scanning the Internet for computers with open Server Message Block ports, then using the EternalBlue SMB exploit to install the ransomware. Once installed on any computer, WannaCry spread to other vulnerable computers on the same local network (LAN). Earlier assumptions about WannaCry using spam and phishing emails to spread were not accurate.

WannaCrypt variants infecting systems worldwide

The accidental stifling of WannaCrypt’s spread was too good to last, apparently. New versions of the ransomware — unaffected by the serendipitous domain registration of a security researcher — are now making their way around the world. You can even watch the malware spread using MalwareTech’s WannaCrypt live feed.

Our advice remains the same: make sure all your Windows computers have the relevant updates installed, including Windows XP. Microsoft’s Customer Guidance for WannaCrypt attacks is a good place to start; there are links to the updates at the bottom of that page. For more information about the exploit used by WannaCrypt, see Microsoft’s MS17-010 bulletin from March 14.

SANS has a good summary of the technical aspects of WannaCrypt.

Update 2017May16: There’s plenty of blame to go around for this mess. Microsoft is being criticized for abandoning Windows XP when it’s still widely used. Meanwhile, Microsoft is blaming the NSA’s vulnerability hoarding.

WannaCrypt ransomware: Microsoft issues updates for unsupported Windows

Ransomware known as WannaCrypt (aka WCry, WannaCry) has already crippled as many as 75,000 unpatched Windows computers in Europe and Asia. So far it hasn’t done much damage in North America, but that could change quickly.

The flaw WannaCrypt uses to infect Windows computers was patched by Microsoft in March, but unpatched computers and those running unsupported versions of Windows were left unprotected.

Microsoft has long since stopped releasing security updates for Windows XP, but WannaCrypt is spreading quickly, and Windows XP computers are essentially defenseless against it. So Microsoft has taken the unprecedented step of publicly releasing an update that protects Windows XP computers from the flaw that WannaCrypt uses to spread.

If you manage any computers that run Windows XP, you should install the update immediately: download update for 32-bit Windows XP Service Pack 3. There’s more information about this from Microsoft.

Techdirt points out that the flaw WannaCrypt exploits was exposed in the recent NSA tool leaks. Which is exactly the problem when security organizations hoard flaws instead of reporting them responsibly.

Update 2017May14: Apparently a security researcher at MalwareTech registered a (previously unregistered) domain used by WannaCrypt as part of his investigation into the ransomware. This is standard practice, because it often allows researchers to gain a better understanding of their subject. Surprisingly, this move stopped WannaCrypt from doing any further damage.

The latest guidance from NCSC.

Flash 25.0.0.171

Adobe’s software updates for April include Flash 25.0.0.171, which fixes seven security issues in previous versions. If Flash is enabled in your web browser, you should visit the official Flash About page to check its version and update if it’s not current.

As usual, Chrome will update itself with the latest Flash, and Internet Explorer and Edge get their new Flash via Windows Update.

Patch Tuesday for May 2017

Well, I was right. The announcement for May’s Patch Tuesday has almost exactly the same wording as last month’s. That’s because neither contains any useful information. No, it’s back to the new Security Update Guide, at least if you want to know what Microsoft wants to do to your computer this month.

According to my analysis of this month’s update information in the SUG, there are fifty distinct bulletins, affecting Flash, Internet Explorer, Edge, .NET, Office, and Windows. A total of fifty-six vulnerabilities are addressed. Fifteen of the vulnerabilities are categorized as Critical.

Today Microsoft also issued three advisories:

Vulnerability in Microsoft’s anti-malware software

All of Microsoft’s anti-malware software is based on a common core: MsMpEng, the Malware Protection service. That includes Microsoft Security Essentials, System Centre Endpoint Protection, and Windows Defender. If your PC is running Windows, there’s a good chance that MsMpEng is running as well.

Which is bad, because Google’s Project Zero just discovered a vulnerability in Microsoft’s anti-malware engine that has the potential to provide almost unlimited access to any computer running MsMpEng. The vulnerability can be exploited in various ways, including via specially-crafted email that can do its damage without even being opened.

Project Zero’s analysis includes a proof of concept, and shows that the vulnerable component of MsMpEng is nscript, which analyzes any file or activity that appears to be Javascript.

I just checked my Windows 8.1 test PC, and although Windows Defender is disabled, MpMpEng is running, describing itself as ‘Antimalware Service Executable’. On my Windows 7 test PC, I’ve installed Avast, which was supposed to have disabled Microsoft’s software; but again I see that MsMpEng is running.

If Windows Defender is disabled, why is MsMpEng running? If it’s disabled, is the computer still vulnerable to this exploit? I’d like to think that even though MsMpEng is running, it’s not actively analyzing file and network activity, in which case the vulnerability would be mitigated. But it’s difficult to know for sure.

In any case, Microsoft has issued an update, and since all of their various anti-malware offerings update themselves automatically, most Windows systems may already have the necessary fix in place. You can find out by checking your software’s ‘About’ information. For example, if you’re running Windows Defender for Windows 8.1, double-click the blue shield icon to open its interface, then click the small triangle next to Help and select About. In the About dialog, look for Engine Version; if it’s 1.1.13704.0 or later, it’s up to date.

Report from Ars Technica.