Be aware of phishing

Following Russia’s attack on Ukraine, the National Cyber Security Centre (NCSC) is calling on all UK organisations to increase their vigilance for cyber attacks.

It is clear that various groups are now using this crisis as an opportunity to launch new phishing email attacks. For example, there are scams asking people to "Help Ukraine" and other scams are based on fake reports of "unusual sign-on activity"

You must always be very wary of any email which wants you to enter personal details or transfer money. The NCSC provides guidance on how to spot scam emails.

If you are unsure of the safety of any emails you receive please contact the Informatics Computing Team via the support form linked from our help site.

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Network switch reboots

It’s time for us to arrange to reboot most of our network switches again.  We need to do this for a couple of reasons.

The first is that the clocks that they use for management and reporting purposes tick in centiseconds.  That means that they wrap at just under 497 days of uptime, which in particular results in error log messages being jumbled.

The second reason is to apply firmware updates.  We apply important updates as soon as we can, of course, but this “yearly” reboot allows us to remain using a (reasonably) current version, which can be important when talking to the manufacturer or swapping individual components.

We had hoped that we could take advantage of the forthcoming electrical work in the Forum and Bayes to do these reboots for us, but unfortunately the likely timing of this now means that we can’t wait so we’ll have to schedule reboots sooner.  For Appleton Tower we usually reboot each floor’s switches first thing in the morning over a couple of days, avoiding major deadlines.

We also have six core switches, for which we always schedule reboots in advance.  These are normally done over a series of lunch-times, as the manufacturer advises that physical intervention may be required in a small number of cases.

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Changes to University DMARC record

To make it harder for spammers and scammers to forge email claiming to originate from the ed.ac.uk domain, the University will shortly be changing the DMARC sub-domain policy (sp argument) to “reject”.

This change will tell any mail services that use DMARC and SPF  tests when validating email, that any email that fails the SPF test for any *.ed.ac.uk, that it is recommended that the mail be rejected.

This, if we did nothing, could affect mail being sent as from @inf.ed.ac.uk addresses. However we have a DMARC record for inf.ed.ac.uk which currently sets our policy as “none”, which will take precedence over the ed.ac.uk’s sp=reject.

Users are unlikely to notice any change (other than hopefully a reduction in forged email claiming to come from a legacy domain like @dai.ed.ac.uk).

However if you are sending mail as coming From: an address that is not @ed.ac.uk or @inf.ed.ac.uk, then mail relays may start flagging your mail as suspicious, and marking it as spam.

Similarly if you are sending mail as From: @ed.ac.uk or @inf.ed.ac.uk but not using the Informatics or University relays as your outgoing SMTP server, then again other relays may see your mail as suspicious and flag it as spam.

Neil

Update 7/2/2022 – Currently this proposed change has been postponed, but will happen at some point in the future

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Wireless Access Point Replacement

As part of the EdLAN replacement project, contractors are working their way round all of the University’s buildings to swap out the wireless access points for new ones.  The Bayes building has already been done (on Tuesday 18th January), and the Informatics Forum is the next one where we’ll see this happen.  This is scheduled for Monday 31st January.  (Appleton Tower isn’t scheduled yet.)

On the day there will be a couple of teams working their way around the building.  They’ll swap one access point at a time, and then test it before moving on to the next one.  While they’re near you you may notice your wireless connectivity becoming a little less reliable than usual, but this should recover as each new AP comes on-line.  Our own techs will be on hand to assist them with access to restricted areas of the building.

Please note: this is a one-for-one replacement, and APs are not being relocated or additional ones added at this time.  We know there are some areas of the building where wireless coverage is less than ideal, and we expect that a subsequent phase of the project will resurvey the building and move or add APs to improve things.

IS are now publishing a “progress page“, where you can find more details on the EdLAN roll-out.

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New student compute servers

Sometimes you need to run software which needs a lot of oomph behind it, and which can take days to run. It’s a bit impractical to run that sort of thing on a normal desktop – which is why Informatics has compute servers.

Until recently there was one for staff (called staff.compute.inf.ed.ac.uk) and one for students (called student.compute.inf.ed.ac.uk). Postgraduate research students were able to use both of these.

However, we noticed that both machines were being heavily loaded with postgrad research student jobs, so we’ve provided several more compute servers. These ones are especially for the use of postgrad research students.

If you’re a postgrad research student, you can login to a new compute server like this:

ssh yourusername.pgr.inf.ed.ac.uk

… where yourusername is your DICE username, for example s1234567:

ssh s1234567.pgr.inf.ed.ac.uk

Edit: That command will work if you’re logging in from a DICE machine, but if you’re logging in from your own machine, you’ll also need to specify your DICE username, like this:

ssh -l yourusername yourusername.pgr.inf.ed.ac.uk

… where yourusername is your DICE username.

There are several of these new servers. Please use only the one which your pgr.inf.ed.ac.uk address takes you to, to be fair to your fellow students.

Now that the postgrad research students have their own compute servers, student.compute.inf.ed.ac.uk is reserved for taught students (undergraduate and MSc).

There’s a help page about compute servers at: https://computing.help.inf.ed.ac.uk/compute-servers.

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log4shell security vulnerability

By now most people are probably aware of the recent discovery of multiple critical security issues in the Java log4j logging library (version 2) which have been named “log4shell“. In some circumstances, these flaws can give attackers the ability to remotely execute their code on our systems. An overview can be found on Wikipedia.

Since the issue was first announced, just over a week ago, computing staff within the School and our colleagues in IS have been working very hard to ensure that this issue does not lead to our computing infrastructure being compromised. We have scanned all externally accessible websites to look for evidence of exploitable systems. We have also scanned all home directories, group space, and local system disks for vulnerable log4j library versions. We are now in the process of contacting all those who own files that contain insecure versions of log4j. If you are contacted you must resolve the issue as soon as possible. We are happy to advise or help if you are not sure of the best course of action to take.

We are also aware of security issues in the old unsupported 1.2 series of the log4j library. Those issues are not currently considered to be as critical so we are currently focussing our efforts on version 2. In the New Year, we will begin contacting people with software that uses 1.2

The log4j library is bundled with many other Java libraries and software so it’s not always obvious that you have it installed. Software distributors are in the process of providing updates, you must apply them as soon as they become available. Most Linux distributors have already updated the version they provide. If you bundle the code with your own projects you can download the latest version from the project website.

If you have any questions about this issue or need help with fixing log4j please contact us via our Support Form.

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A second student compute server

We’ve added a second student compute server, and it’s called student2.compute.inf.ed.ac.uk.
Students can login to it like this:

ssh student2.compute.inf.ed.ac.uk

We’ve done this because in recent days the student compute server (student.compute.inf.ed.ac.uk) has been unresponsive at times, because it’s been used so enthusiastically.
There’s a range of things we could do to help, and we’re still looking at other options, but for the time being we’ve introduced the second compute server.
Once again – to login, type:

ssh student2.compute.inf.ed.ac.uk
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Changes to the SSH service

The way in which SSH login services are provided for the School of Informatics will soon be changing.

Continue reading

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Virtual DICE for 2021-22

The 2021-22 version of Virtual DICE is now available.

Virtual DICE is like the School of Informatics’ DICE Linux environment, except that you can run it on your own computer in a virtual machine.

If your computer can run VirtualBox, and has an Intel architecture, then Virtual DICE should run on it.

We’ve just released the latest version of Virtual DICE, and it’s free for you to download and install. You can read all about it on the Virtual DICE help pages.

It comes in two editions. If you want to use Virtual DICE for coursework, you should choose the teaching edition. To learn more, see the Virtual DICE help pages.

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Access to ifile.inf.ed.ac.uk restricted

Access to the ifile.inf.ed.ac.uk service has been restricted to the University (and therefor also the Informatics) networks.

Previously you could directly access ifile.inf.ed.ac.uk from anywhere, but now if you are at home, for example, you will first need to connect to the University or Informatics VPN service to make your device look like it is within the University network.

We have had to do this because the software that provides the ifile service is no longer maintained, and relies on an out of date web framework. With the increasing concern about the vulnerability of old, out of date software, which are often used as attack routes by hackers, this restriction will remove the ability for the bad guys on the outside to keep picking and prodding away trying to gain access.

Admittedly this restriction somewhat reduces the usefulness of the ifile service. If we do find a current, maintained equivalent software package, then we can look at upgrading ifile and removing this restriction.

Remember that if you have an ssh access to an Informatics machine, you could use scp/sftp to access the AFS file system.

Neil
Services Unit

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