The Conference Hotel Booking Scam

Something interesting happened to me in the last few days. To my knowledge, this seems to be a scam, and to be something relatively new, so I want to share the information.

Here is the context. I will be a keynote speaker at a conference in Asia in a few months, and out of the blue, a company that appeared to be based in the Netherlands contacted me a few days ago by email offering to arrange my hotel accommodation. At first, the email from “ExploreEra Reservations” (reservation.nl@exploreera.info) looked very professional. They mentioned the conference location and month, and politely asked for my exact arrival and departure dates to reserve my hotel room. Their email was worded in the kind of tone you might expect from a real conference travel desk. Here is a screenshot:

But there was some red flag already in this e-mail, such as indicating that they require 30 days to cancel the reservation, which is highly unusual. In fact, a hotel reservation can in general be cancelled in 24 hours for most hotels without fees. But I still responded with basic details about my dates to see what they would say. In the follow-up email, there was more serious red flags. Here is a screenshot:

At about the same time as this, in a separated e-mail, they sent me a PandaDoc form for a hotel booking with a proposed rate of €200 per night, while also asking for personal information and a signature, and there was a weird disclaimer in small print indicating that they are not affiliated to the conference (very suspicious!), and there are HUGE cancellation fees:


Thus, I decided to investigate this. I Googled the proposed hotel name and found that their real rate is more like 20-50 euros per night on Booking DOT com, not 199 euros.

Then, I googled their organization — ExploreEra.info — and quickly discovered that at least two conferences have issued very serious warnings about emails from this domain approaching their attendees to book hotels on their behalf without authorization.

For example, the World Psychiatric Association (WPA) posted an alert noting that emails from ExploreEra.info have been contacting their delegates, pretending to arrange accommodation on behalf of the conference. Here is a screenshot of this warning:

Another event also issued a similar warning:


So, is this a scam? Well, in the emails I have received, they never mentioned directly that they work for the conference, but the emails are worded in a way that gives this impression. And based on the above warnings from other conferences, and the apparently inflated price and 30 days cancellation policy, it seems indeed to be a scam. Thus, be warned!

By the way, there are several messages on Twitter warning about similar schemes, although I dont know if it is from the same people:

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Huge traffic from a botnet looking for datasets

Today, I received an e-mail from the Web hosting company indicating that my website had exceeded the bandwidth limit of the content delivery network (CDN) for my package. I was quite surprised. Hence, I checked the control panel, and I saw a huge increase in bandwidth for the last three days, as shown below (in GBs).

By looking at the logs, I saw that some bots from thousands of different addresses where trying to access datasets from the SPMF website using malformed URLs with multiple times the word “datasets” inside. Here is an excerpt from the logs:

These URLs do not exist, however due to the configurations of the server, they were redirected to the real dataset URLs thus and consuming a huge amount of bandwidth.

Since all the requests came from different IPs from dozen different countries, it would not be realistic to ban all the IP addresses.

Thus, I have check how to fix the configuration. Finally, I modified the .htaccess file of the server to block malformed requests and also deactivate the default fuzzy URL matching done by the server to match paths that dont exist with real paths on the server. This may have caused some slight issue on the website during the last hours. But now, I think that the problem is fixed and the website will be faster!

So why my website was flooded by requests for datasets? I think that the most likely reason is that some people have decided to launch a web scraping botnet for data, and that the bot is buggy such that it would recursively add /datasets/ to the same path dozens of times like in this URL:

… /spmf/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/datasets/costtrans/datasets/onshelf/datasets/husp/datasets/husp/datasets/husp/BIBLE_sequence_utility.txt

Than the botnet would not realize that it is actually always downloading the same files over and over again from similar URLs….

Update a few hours later: I see that my new rules in .htaccess are working as now all invalid requests are now blocked:

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New version of SPMF: 2.63!

This is just a short blog post to let you know that SPMF 2.63 is released on the SPMF website, with some new features such as the Visual Pattern Viewer (to display patterns visually), and also some new algorithms and several bug fixes.

The list of changes in SPMF 2.64 can be found on the download page.

Here, just to give you a glimpse of this new version, here is a screenshot of the Visual Pattern Viewer, utilized for viewing sequential patterns:

The Visual Pattern Viewer can be used to explore patterns visually with search and filter function and can display a large number of different pattern types like association rules, itemsets and more.

And here is the list of new algorithms in SPMF 2.63:

  • The EMDO algorithm for mining frequent parallel episodes and episode rules in complex event sequences by counting distinct occurrences (thanks to Oualid Ouarem et al. for the original code).
  • the EMDO-Rules for generating episode rules from parallel episodes found by EMDO. (Ouarem et al., 2024) new
  • The RMiner algorithm for high utility itemset mining (thanks to Pushp Sra et al. for the original code).
  • The ScentedUtilityMiner algorithm for high utility itemset mining with a recency constraint using reinduction counters (thanks to Pushp Sra et al. for the original code).
  • The Density Peak Clustering (DPC) algorithm for clustering vectors of numbers
  • The AEDBScan algorithm for clustering vectors of numbers

What’s next?

The development of SPMF is always ongoing. If you want to contribute code of new algorithms, feel free to contact with me with your code.

Hope you enjoy this new version of SPMF. For the next version 2.64, there will be more new algorithms and some further performance improvement. I expect that it would be released this Autumn.

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Upcoming feature of SPMF 2.63: Taxonomy Viewer

Today, I want to share briefly a new feature of the upcoming SPMF version 2.63, which is the taxonomy viewer. This tools allow to visualize a taxonomy used by algorithms such as CLH-Miner and FEACP.

The user interface is for now quite simple and looks like this:

In this example, I display a file called transaction_CLHMiner.txt, which defines the taxonomy:
1,6
2,6
3,7
4,8
5,8
6,7
9,1
10,1

And a transaction database given names to these items in a file taxonomy_CLHMiner.txt:

@ITEM=1=apple
@ITEM=2=orange
@ITEM=3=milk
@ITEM=4=bread
@ITEM=5=bagel
@ITEM=6=orange
@ITEM=7=FreshProducts
@ITEM=8=BreadProducts
@ITEM=9=red_apple
@ITEM=10=green_apple
1 3:6:5 1
5:3:3
1 2 3 4 5:25:5 10 1 6 3
2 3 4 5:20:8 3 6 3
1 3 4:8:5 1 2
1 3 5:22:10 6 6
2 3 5:9:4 2 3

This is just to give you a preview of some new features of SPMF. The next version should be released in about 1 week!

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CFP: The OCSA 2025 conference

Today, I would like to share the call for papers for the upcoming OCSA 2025 conference, which will be held in Changsha, capital of the Hunan province of China. The details of the conference are as follows:

International Conference on Optoelectronics, Computer Science, and Algorithms (OCSA 2025)
Website: www.icocsa.net
Email: ocsa@163.com
Dates: September 19-21, 2025
Venue: Changsha, China
Indexing: EI database (pending approval)
Submission link: https://ocs.academiccenter.com/manager/dashboard

If you are interested, you may consider submitting a paper.

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Update on SPMF next version: the visual pattern viewer

I am still working on the upcoming version of SPMF. There is still much work todo. Following the previous post, I would like to give you a glimpse of the new visual pattern viewer that is under development for SPMF. This is a new tool that will allow to see patterns visually and search and filter them. It will be well-designed and will work with most pattern types that can be produced by SPMF. Here is a picture of the current version:

On that picture we can see a list of high utility sequential patterns displayed as a grid, where the utility of each pattern is displayed using a colored bar that varies from 0 to the maximum utility observed among the patterns in this example, which is 40. On the right, there is a search panel to filter the pattern by utility values or to search for a specific itemsets. In this example, only the patterns with a utility of at least 37 are displayed using the filter. In the menu bar, we can also sort the patterns by different orders:

For example, above the patterns were displayed by decreasing number of itemsets. We can change this to display them by ascending utility, and remove the filters, to obtain this:

Now, let me show you other pattern types. Here are high utility sequential rules:

And here are frequent high utility itemsets:

Update: I have fixed the alignment of colored bars representing measures. And the different measures are now displayed with different colors:

Conclusion

This is just an overview of this upcoming tool that will be incorporated in the new version of SPMF. If you have suggestions, please leave a comment below. Note also that this tool is under development. The released version may be different and have additional features.

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CFP: HP4MoDa 2025 @ IEEE BIBM 2025

Today, I would like to announce a new workshop that will be held at the IEEE BIBM 2025 conference, called 1st Workshop on Heuristic and Pattern Mining for Multi-Omics Data Analytics.

This workshop is suitable for pattern mining papers and machine learning, especially with applications to bioinformatics. The scope is quite large. You may the HP4MoDa workshop website for more details or e-mail me if you are not sure if your paper fit in the scope of the workshop!

A good thing is that the workshop will be in Hybrid mode, which means that participants can present their papers online or offline in Wuhan, China.

The dates are as follows:

  • Paper Submission: October 15, 2025
  • Acceptance Notification: November 10, 2025
  • Camera-ready Submission: November 23, 2025
  • Workshop date: December 15, 2025

All papers will be published in the regular conference proceedings of IEEE BIBM And we are planning to organize a special issue in a good journal as well (under discussion).

Hope to see your submission soon!

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An Improved Pattern Viewer

Today, I will talk about some features of the upcoming version of SPMF 2.63 that I am working on and is planned for release next month.

Improved Pattern Visualizer window

The first feature is an improvement of the Pattern Viewer tool so that it can display the richer SPMF format where items have names (strings) in patterns. Previously, a pattern file like this:

@ITEM=1=apple
@ITEM=2=orange
@ITEM=3=tomato
@ITEM=4=milk
@ITEM=5=bread
1 2 4 5
2 3 5
1 2 4 5
1 2 3 5
1 2 3 4 5
2 3 4

would be displayed as this by the Pattern Viewer:

Now, it is displayed as:

Other pattern visualizations

I am also working on adding other tools for visualization such as a Rule Viewer to visualize association rules and sequential rules like this:

The above screenshot is an early version. I will improve the appearance of this window and I still have to think about how to best integrate it in the software.

Today, I just wanted to show you some ideas of new features. If you have any ideas or comments, send me an e-mail or leave a comment below!

Posted in Data Mining, Data science, Java, open-source, Pattern Mining, spmf | Tagged , , , , , , , , , , | 3 Comments

Computer Science Journals and Conferences with the most withdrawals in 2024

We are now in 2025, and like last year, I will analyze the list of the computer science journals and conferences with the most withdrawal for the previous year (see this blog post for 2023).

Methodology

To verify how many papers have been withdrawn or retracted for the computer science field in 2024, I search in the DBLP database using the following query (access = withdrawn, year = 2024):
https://dblp.org/search/publ?q=access%3Awithdrawn%3A%20year%3A2024%3A

Thus, I only consider journal and conferences that are indexed in DBLP, which covers the best journals and conferences in computer science. I also only consider venues with at least 2 withdrawn papers.

Results

RankJournal NameWithdrawn paper Count
1 ▲J. Intell. Fuzzy Syst.45 ▲ (last year: 2)
2 – Multim. Tools Appl.27 ▼ (last year: 37)
3 ▲Ann. Oper. Res.23▲ (last year: 2)
4Expert Syst. J. Knowl. Eng.20▲ (new)
5Trans. Emerg. Telecommun. Technol.11 ▲ (new)
6Int. J. Speech Technol.9▲(new)
7 ▲Pers. Ubiquitous Comput.9▲ (last year: 6)
8Comput. Intell.9▲ (new)
9Int. J. Pervasive Comput. Commun.7▲ (new)
10 ▲EURASIP J. Inf. Secur.6▼(last year 5)
11J. Ambient Intell. Humaniz. Comput.4▲ (new)
12 ▲Neural Comput. Appl.3– (last year: 3)
13Biomed. Signal Process. Control.3▲(new)
14Int. J. Hum. Comput. Interact.3▲ (new)
15Phys. Commun.2▲(new)
16Int. J. Commun. Syst.2▲(new)
17 ▲Wirel. Pers. Commun.2– (last year: 2)

By looking at this table and comparing with year 2023, some observations can be made.

First, the first position in the table has 45 withdrawn articles, which is much less than the 133 articles in Soft Computing from last year. In fact, Soft Computing is not in the table this year.

The top 3 positions in the table (J. Intell. Fuzzy Syst., Multim. Tools, Appl., and Ann. Oper Res.) were also in the table last year. Let’s analyse these three journals in more details:

For the Multimedia Tools and Applications journal, the number of withdrawn papers decreased from 37 to 27. But according to LetPub, the journal was expelled from the SCIE index on October 22, 2024.

The number of papers in the Journal of Intelligent Fuzzy Systems increased from 2 to 45. According to LetPub, this journal is still on hold.

As for the Annals of operations research Journal, the number of withdrawn papers increased from 2 to 23.

In the rest of the table, most of the entries are new. It is interesting that this year, there are no conferences in the ranking. Last year, it was quite surprising to see that the CVPR conference had three withdrawn papers.

Conclusion

This is short blog post to give some update about his metric of withdrawn papers per journals and conferences.

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Unusual Web traffic and end of the forum.

Hi all! Today, I write a blog post to announce that I have decided to close the data mining forum, which was hosted on this website at http://forum2.philippe-fournier-viger.com/ . The forum was a small website that was connected to my other websites. The forum was used for discussing about data mining topics and was powered by a version of PhPBB. I will now explain why I decided to close the forum and what happened.

First, let’s go back in time to a few weeks ago, in early March 2025. I was trying to access my main website, and I noticed that my website periodically became unavailable with this error: Error 500: Internal Server Error.

I would try to connect to any pages of my website and this error would sometimes occur and sometimes it would not. I first thought that there was a problem with the server hosting my website. I pay a webhosting company to host my websites. So, I logged into the administration panel of my websites and looked. I did not found anything suspicious. Then, after a few hours, my website started to work again, so I thought that it was a temporary problem and that it was solved.

But no! Today, on April 7th 2025, the website went down again and was barely accessible for the whole morning. Then, I started to investigate again. I decided to download all the access logs from the server to see if I could get some idea about what was going on.

Here is what I found. First, I looked at the summary of the HTTP requests to my websites by months:

As you can see above, the number of requests was around 3 million per month in 2024 but suddenly in March it increased 10 times to around 32 million requests per month, which is extremely suspicious.

Then, I looked at the data for the first days of April, and I found that the number of requests even peaked at 6 million per day, which is a ridiculously high number for my small website.

Then, I looked into the detailed log and found that more than 90 % of the requests were coming from Brazil and were made to access different pages from my forum. Here is a sample of some of those requests:

As can be seen in the screenshot above, dozen of requests were sent from multiple IP addresses, mainly from Brazil with the same timestamp.

I then did a reverse lookup of some of these IP addresses to find where it came from and found that these IP addresses belong to some internet providers in Brazil.

It is not clear why this unusual traffic happened. But the most likely explanation is that some bots decided to try to spam my forum with advertisements and repeatedly tried to login and post. In my forum, the bots were unable to post since I required the manual approval for all new users. However, this did not discourage bots from accessing my webpage millions of times to the point of causing all my websites to go down.

Facing this situation, I had to decide whether to try to block all requests from Brazil, or to improve the security of the website or of the forum itself. But since all the requests were coming from different IPs, it is not simple. And I do not want to pay for some extra security service.

Thus, for this reason and because few people were using the forum in recent years, I have decided to just close it. As few people were using it, I think that it is not a big issue. In the future, I might prepare an alternative to the forum that will be more modern perhaps like a Reddit group or a WhatsApp group. If you have suggestions, feel free to let me know below in the comment section

And since I have closed the forum, the speed of this website and all my other websites has greatly increased!

So that’s the story about this! Hope this blog post has been interesting.

Update 1 (9th April – 1 day later) – traffic decrease: The number of HTTP requests has largely dropped after closing the forum:

This confirms that the forum was a magnet for bots and spam, and it was a good decision to close it.

Update 2 (12th April) – robots traffic, and CDN

I have done further analysis on the traffic to my websites, and it is also interesting to see that much traffic is by these bots:

And some bots do not bring any meaningful benefit to my websites. For instance, AhrefsBot and AwarioBot are primarily used for SEO monitoring and competitor analysis. Since I do not use these services, allowing their bots to crawl my website only consumes bandwidth without offering any benefits. Similarly, TurnitinBot index content for proprietary systems. Hence, to prevent these bots from crawling my website, I’ve added the following rewrite rule to my .htaccess file:

RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (GPTBot|AwarioBot|TurnitinBot|AhrefsBot|SemrushBot|DotBot) [NC]
RewriteRule .* - [F,L]

This rule ensures that these bots receive a 403 Forbidden response and are effectively blocked from accessing any part of the website. This should improve a little bit more the website performance.

Besides, today I also reactivated the CDN (Content Delivery Network) with CloudFare for this website to boost the speed.

That’s all for today! Thanks for reading.

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