My Spam analysis & filter updates for the week of Aug 7 - 14, 2011
This week I saw an increase in the amount of spam hitting my inbox. The percentage of spam was up 7% from the previous week. Actually, the greatest volume of spam occurred from Thursday through today. It was on August 11 that a giant spam run began with malware infected attachments, in scam emails claiming to be from the IRS and UPS.
Due to the huge influx of malware laden attachments in fake IRS ("could not process your return/refund") and UPS ("your package delivered ... print out invoice") messages, the top category last week was Zip file attachments, which led by more than double the amount of the runner up: male enhancement. While the enhancement and enlargement spam is a nuisance, the ones pretending to come from the IRS and UPS were downright dangerous. They contain botnet and key logging Trojans in zip files.
This past 7 days, spam for various types of unsolicited commercial email (UCE) 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 Aug 7 - 14, 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%; +7% from last week
Number of messages classified as spam: 128
Number classified by my custom spam filters: 122
Number and percentage of spam according to my custom blacklist: 3
Number classified as spam by the Bayesian Learning filter: 0
Number classified as spam according to DNS Blocklists (SpamCop, Spamhaus, etc): 1
Number of spam messages seen, reported to SpamCop & manually deleted: 52
The actual percentages of spam by category follow below.
The order of spam categories, according to the highest percentages, is as follows:
Zip, Rar, Gz Attachments (malware!): 37.30%
Male Enhancement scams: 15.87%
Fake Cialis:9.52%
Weight Loss Scams (e.g. HCG): 7.14%
Known Spam Domains: 6.35%
URL Shortener spam link: 3.17%
Hidden ISO Subject: 2.38%
Counterfeit Watches: 2.38% (way down from last week!)
Pharmaceuticals spam: 2.38%
My Custom Blacklist: 2.38%
Base64 spam encoded message: 1.59%
DNS Blacklists (SpamCop, Spamhaus, etc): 0.79%
Other Filters (with small individual percentages): 8.73%
This week I made 1 update and/or additions to my custom filters:
Pump and Dump Scam
I made 1 addition to my custom Blacklist this week:
+@best*offers.com
There was one false positives last week, resulting in the removal of just one letter, from the Male Enhancement filter. All other filters behaved as intended, or as updated. My filters are published in both the old and new MailWasher Pro formats. 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? Not only does it detect and block spam, but can also protect your PC from downloading harmful viruses, or other known threats.
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