My Spam analysis & filter updates for the week of July 17-24, 2011
This week, my incoming spam level was just 1% lower than last week. However, the types of spam have begun to change in order of percentages by category. Some previously strong categories have dropped way down as spammers find them unprofitable.
Spammers are using a new template that adds huge amounts of spacebar spaces between the spam words in the plain text source code. This is followed by HTML content that is identical. However, when HTML is rendered, only one space is shown between words, making the actual spam message readable by a member of the Human Race. Writing a filter for this trick is trivial. I already have one for Diploma Spam using the multiple spaces and am in the process of creating another for pharmacy spam.
This past 7 days, spam for various types of garbage amounted to 28% of my incoming email. This is according to MailWasher Pro, which I use to screen incoming email before downloading it to my desktop email program (Windows Live Mail). I report any spam messages that make it through my auto-delete filters to SpamCop.
Here are some statistics regarding the spam received and categorized, from July 17-24, 2011. These classifications are based upon my own custom MailWasher spam filters. Most of this spam is automatically deleted by MailWasher Pro and my custom filters. The statistics are obtained from the program's logs.
Statistics Overview
Percentage classified as spam: 28%; -1% from last week
Number of messages classified as spam: 124
Number classified by my custom spam filters: 115
Number and percentage of spam according to my custom blacklist: 5
Number classified as spam by the Bayesian Learning filter: 0
Number classified as spam according to DNS Blocklists (SpamCop, Spamhaus, etc): 4
Number of spam messages seen, reported to SpamCop & manually deleted: 22
The order of spam categories, according to the highest percentages, is as follows:
Male Enhancement scams: 20.97%
Fake Viagra and Cialis: 20.97%
Pharmaceuticals (unlawful to import into the USA): 13.71%
Weight Loss Scams (e.g. HCG): 9.68%
URL Shortener Spam Link: 8.06%
Diploma Spam: 5.65%
Other Filters (with small individual percentages): 4.84%
My Custom Blacklist: 4.03%
DNS Blacklisted Servers (e.g. SpamCop, Spamhaus): 3.23%
Counterfeit Watches: 2.42% (Way down from last week!)
Known Spam Domains: 2.42%
.BR, .CN, .RU, .UA spam domain links: 2.42%
Non-English Language spam (Bad Robot !): 1.61%
This week I made 6 updates and/or additions to my custom filters:
Updated (for huge # spaces around words) and split Diploma Spam into 3 filters
Diploma Spam [B plain text],
Pharmaceuticals [S],
Re: or Fw: Spam,
URL Shortener Spam Link,
Work At Home Scam
I made 1 addition to my custom Blacklist this week:
[email protected] (use at your own discretion!)
There were no false positives last week. All filters behaved as intended. Note, that I now publish three types of spam filters for MailWasher Pro. One type is for the latest 2011 series, in xml format, and two are for the previous series 6.x. One of those filters is set for manual deletions and the other for automatic deletions. You can read all about MailWasher Pro and the filters I write for it, on my MailWasher Pro Custom Filters page.
If you are having trouble caused by excess volumes of spam email, and are not using an effective filter, why not try out MailWasher Pro? It sure works for me!
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