Threat Intelligence

Threat Intelligence / Most Viewed

Greylisting Still Works - Part II

In my last post I blogged about greylisting, a well-known anti-spam technique for rejecting spam sent by botnets. When a mail server receives a an attempt to deliver mail from an IP address that's never sent mail before, it rejects the message with a "soft fail" error which tells the sender to try again later. Real mail senders always retry, badly written spamware often doesn't. I found that even though everyone knows about greylisting, about 2/3 of IPs don't successfully retry. more

DNS Amplification Attacks: Out of Sight, Out of Mind? (Part 2)

This post follows an earlier post about DNS amplification attacks being observed around the world. DNS Amplification Attacks are occurring regularly and even though they aren't generating headlines targets have to deal with floods of traffic and ISP infrastructure is needlessly stressed -- load balancers fail, network links get saturated, and servers get overloaded. And far more intense attacks can be launched at any time. more

Israel’s Entire Voter Registry Exposed, the Massive Data Leak Involves 6.5 Million Voters

Israel's entire voter registry was recently uploaded to a vulnerable voting management app which effectively left the data wide open for days. more

ICANN: The Stakes in Registrar Accreditation

Law enforcement demands to domain name registrars were a recurring theme of the 42d ICANN public meeting, concluded last week in Dakar. The Governmental Advisory Committee (GAC) took every opportunity at its public meetings with GNSO and Board, and in its Communique to express dismay, disappointment, and demands for urgent action to "reduce the risk of criminal abuse of the domain name system." more

Microsoft Disrupts the Zeus Infrastructure

Over the weekend and this morning, Microsoft, working in conjunction with others, issued civil lawsuits to sinkhole numerous domains associated with the Zeus botnet. When I say "botnet", I use the term loosely because Zeus is not a botnet in the sense that Rustock or Waledac is (or was). Rather, Zeus is a tool kit that online criminals can buy that lets them create phishing pages, perform fast fluxing, host drive-by downloads in addition to spamming. It's more like infrastructure than a botnet, although it does have a large botnet under its control. more

Are Botnets Really the Spam Problem?

Over the last few years I've been hearing some people claim that botnets are the real spam problem and that if you can find a sender then they're not a problem. Much of this is said in the context of hating on Canada for passing a law that requires senders actually get permission before sending email. Botnets are a problem online. They're a problem in a lot of ways. They can be used for denial of service attacks. They can be used to mine bitcoins... more

Cryptographic Tools for Non-Existence in the Domain Name System: NSEC and NSEC3

In my previous post, I described the first broad scale deployment of cryptography in the DNS, known as the Domain Name System Security Extensions (DNSSEC). I described how a name server can enable a requester to validate the correctness of a "positive" response to a query -- when a queried domain name exists -- by adding a digital signature to the DNS response returned. more

SPIT is in Everyone’s Mouth, Though Not Yet in Everyone’s Ears

Spam over Internet Telephony (SPIT) is viewed by many as a daunting threat. SPIT is much more fatal than email spam, for the annoyance and disturbance factor is much higher. Various academic groups and the industry have made some efforts to find ways to mitigate SPIT. Most ideas in that field are leaning on classical IT security concepts such as intrusion detection systems, black-/white-/greylists, Turing tests/computational puzzles, reputation systems, gatekeeper solutions, etc... We identified the lack of a benchmark testbed for SPIT as a serious gap in the current research on the matter, and this motivated us at the to start working on a first tool for that. more

Name Collision Mitigation Requires Qualitative Analysis (Part 3 of 4)

As discussed in the several studies on name collisions published to date, determining which queries are at risk, and thus how to mitigate the risk, requires qualitative analysis. Blocking a second level domain (SLD) simply on the basis that it was queried for in a past sample set runs a significant risk of false positives. SLDs that could have been delegated safely may be excluded on quantitative evidence alone, limiting the value of the new gTLD until the status of the SLD can be proven otherwise. more

Compromised Accounts - Are Hotmail, Yahoo and Gmail Seeing an Increase in Spam Sent Out?

Last week, I commented on the the Gmail/Hotmail/Yahoo username and password leak. The question we now ask is whether or not we are seeing an increased amount of spam from those services. On another blog, they were commenting that various experts were claiming that this is the case. more

Neustar Analysis Shows ICANN Study Overstates Risk of Harmful Domain-Name Collision

As we blogged about recently, Neustar is committed to ensuring that the domain name system is secure and stable and has been operating top-level domains (TLDs) for over a decade. Tuesday, Neustar submitted comments to the Internet Corporation for Assigned Names and Numbers (ICANN) in response to ICANN's proposal to delay the launch of hundreds of new generic top-level domains (gTLDs). ICANN's decision to delay the launch is based on a study it commissioned that measured the potential frequency of domain-name collision. more

Phishing: A Look Into the E-Crime Landscape

At the recent Anti-Phishing Working Group meeting in San Francisco, Rod Rasmussen and I published our latest APWG Global Phishing Survey. Phishing is a distinct kind of e-crime, one that's possible to measure and analyze in depth. Our report is a look at how criminals act and react, and what the implications are for the domain name industry. more

The Real Face of Cyberwar?

Anyone who reads the papers sees stories -- or hype -- about cyberwarfare. Can it happen? Has it already happened, in Estonia or Georgia? There has even been a Rand Corporation study on cyberwarfare and cyberdeterrence. I wonder, though, if real cyberwarfare might be more subtle -- perhaps a "cyber cold war"? more

Corporate Espionage in the News: Hilton and the Oil Industry

Is anyone calling espionage by means of computers cyber-espionage yet? I hope not. At least they shouldn't call it cyber war. Two news stories of computerized espionage reached me today. The first, regarding the Oil industry, was sent by Marc Sachs to a SCADA security mailing list we both read. The second, about the hotel industry, was sent by Deb Geisler to science fiction convention runners (SMOFS) mailing list we both read. more

Government and Botnets

The US government is looking at telling ISPs how to deal with compromised customers and botnets. They're a bit late to the party, though. Most of the major commercial ISPs have been implementing significant botnet controls for many years now. more