Articles by Chester Wisniewski

About Chester Wisniewski

Chester Wisniewski is a Senior Security Advisor at Sophos Canada. He provides advice and insight into the latest threats for security and IT professionals with the goal of providing clear guidance on complex topics. You can follow Chester on Twitter as @chetwisniewski, on as Chester, Chester Wisniewski on Google Plus or send him an email at

Adobe fixes critical Flash flaw

Adobe Flash security update for Windows, Mac, Android, Linux and Solaris users

Adobe has released an emergency update to its ubiquitous Flash Player software. The flaw is being exploited by attackers so you should update as soon as possible.

The power of two - All you need to know about two-factor authentication


What can we do to protect ourselves from stolen password databases, phishing attacks, keyloggers or credit card skimmers installed in our local ATMs? We can start with two-factor authentication. This article tells you what it is, how it works and where you can use it.

Privacy is not dead - you're just doing it wrong


Today is Data Privacy Day. While many have declared privacy to be dead, it isn't up to them, it is up to you.

Being aware about what you are sharing with whom can go a long way towards preserving your privacy.

Craft store Michaels faces second credit card compromise in 3 years


The largest craft supply store in North America, Michaels, has indicated it may be the latest retail company to have credit cards compromised in a large scale malware attack.

Patch Tuesday January 2014 - Microsoft, Adobe and Oracle


Microsoft, Adobe and Oracle have all released fixes today. Products covered include Microsoft Word, Windows XP, Windows 7, Adobe Reader, Java, MySQL and VirtualBox.

82% of enterprise Mac users not getting security updates


Apple users are updating to OS X Mavericks in large numbers, but not fast enough. Corporate users in particular have been slow to upgrade, which could have serious security implications.

Skype's Twitter account compromised by Syrian Electronic Army

Microsoft's reading Skype messages

Microsoft's Skype brand had its Twitter, Facebook and WordPress accounts hacked by a someone claiming to be the Syrian Electronic Army. The real question is, where was the two-factor?

Black Friday spams are too good to be true


With the holiday season approaching and lots of super good deals being offered around the American Thanksgiving holiday, retailers aren't the only ones looking to make a buck.

Microsoft leads the way, setting new cryptographic defaults


Microsoft is upping its game with regards to cryptographic standards. By discontinuing support for the older, weak RC4 cipher and putting Certificate Authorities on note to migrate to SHA-2, it seems to be leading the way to be ready for the future, rather than reacting.

Patch Tuesday November 2013 - Microsoft, Adobe and Google

Patch Tuesday

November's Patch Tuesday includes updates not just from Microsoft, but Adobe and Google as well. Critical patches for Internet Explorer, Chrome and Adobe Flash Player lead the way this month.

Apple's iCloud iConundrum - does convenience mean insecurity?


Researcher Vladimir Katalov explained how documents and backups stored in Apple's iCloud can be accessed bypassing Apple's two-factor authentication, even when enabled, last week at the Hack in the Box conference in Malaysia.

SSCC 119.5 - Tips for online safety from security expert Rob Slade


This special Chet Chat is an interview with Robert Slade, author and security expert, on what you can do for your friends and family to help them stay safer for National Cyber Security Awareness Month.

Twitter introducing new direct message options - to combat spam or invite more?

Twitter screws up, sends deluge of password-reset messages

Twitter appears to be rolling out new options to allow the reception of direct messages from users you don't follow and new restrictions on what types of links can be sent through direct messages. Is this a safety feature or does is it too restrictive?

Oracle releases 127 security fixes, 51 for Java alone


Oracle has released its quarterly software update fixing more than 100 security vulnerabilities in its products. Java is at risk from more than 50 flaws, so it is time to update immediately if you still use it.

SSCC 118.99 - How do you define a Potentially Unwanted Application (PUA)?

Google rolls out fix for Android security vulnerability

In the third part of Sophos Security Chet Chat 118, Chet interviews Vanja Svajcer to explain the rise of potentially unwanted applications on Android, what they are and how we might deal with them.

GinMaster, unwanted Android apps and legit apps gone bad


More coverage from the Virus Bulletin 2013 Conference in Berlin, Germany. Today's topics include Android botnets, malware abusing legitimate applications and defining the types of apps we allow on our phones.

Zero Access, vulnerability disclosure and the evils of RTF


Chester Wisniewski writes to us from Virus Bulletin 2013 in Berlin, Germany to share the latest research on malicious documents, bot herders and foos ball.

SophosLabs prepares for great showing at Virus Bulletin 2013

Who is SophosLabs

Sophos has a larger than normal presense this week at the Virus Bulletin Conference in Berlin, Germany. Research presented includes bot nets, rootkits, Android and even techniques we can use to better protect others.

Firefox 24 available now! 17 fixes, 7 critical


The Mozilla Foundation released Firefox, Thunderbird and SeaMonkey version 24.0, fixing 17 vulnerabilities.

Internet Explorer zero-day exploit prompts Microsoft to publish emergency Fix it

Microsoft releases fix for Internet Explorer security hole, full patch coming Friday

Microsoft has published an out of band security advisory for users of Internet Explorer to warn about a new zero-day attack being used in the wild. IE users are advised to use Microsoft's Fix it or EMET tool to protect against exploitation until a permanent fix is released.