Highlights included:
• Image spam continued to decline to an average of 14.5% for the month of June, down from
27% and 37% in the months of April and March respectively. At its peak in January 2007,
Symantec estimated that image spam accounted for nearly 52% of all spam. With the
recent decline in image spam, Symantec has observed an increase in new spam techniques
which reference spam images in different ways.
• Overall spam levels remained consistent for the month of June at the SMTP layer coming in
on average around 65%.
• Scams and fraud spam combined continues to rise from 9% in March to 14% in June.
• Health spam declined from 23% in March to 13% in June
• Additional insight is provided below on the following tactics:
– This month PDF image spam makes a splash
– Free money anyone?
– Current affairs used to peddle medication spam
– As night follows day – Father’s day spam follows Mother’s day spam
– DHA attacks taken to a different level
• Spam spotlight: Regional spam trends APJ
Percentages of Email Identifi ed as Spam
Defi ned:
Worldwide Internet Mail Gateway Spam Percentage represents the number of messages
that were processed and classifi ed as spam versus the total number of messages processed
when scanned at the mail gateway. This metric represents SMTP layer filtering and does not
include the volumes of email detected at the network layer.
Spam Monthly Report, July 2007
Global Spam Categories
Defi ned:
Spam category data is collected from classifi cations on messages passing through the
Symantec Probe Network.
Category Definitions
• Product Email attacks offering or advertising general goods and services. Examples:
devices, investigation services, clothing, makeup
• Adult Email attacks containing or referring to products or services intended for persons
above the age of 18, often offensive or inappropriate. Examples: porn, personal ads,
relationship advice
• Financial Email attacks that contain references or offers related to money, the stock
market or other fi nancial “opportunities.” Examples: investments, credit reports, real estate, loans
• Scams Email attacks recognized as fraudulent, intentionally misguiding, or known to result in fraudulent activity on the part of the sender. Examples: Nigerian investment, pyramid schemes, chain letters
• Health Email attacks offering or advertising health-related products and services. Examples: pharmaceuticals, medical treatments, herbal remedies
• Fraud Email attacks that appear to be from a well-known company, but are not. Also known as “brand spoofi ng” or “phishing,” these messages are often used to trick users into revealing personal information such as email address, fi nancial information and passwords.
Examples: account notifi cation, credit card verifi cation, billing updates
• Leisure Email attacks offering or advertising prizes, awards, or discounted leisure
activities. Examples: vacation offers, online casinos, games
• Internet Email attacks specifi cally offering or advertising Internet or computer-related
goods and services. Examples: web hosting, web design, spamware
• Political Messages advertising a political candidate’s campaign, offers to donate money
to a political party or political cause, offers for products related to a political fi gure/campaign,
etc. Examples: political party, elections, donations
• Spiritual Email attacks with information pertaining to religious or spiritual evangelization
and/or services. Examples: psychics, astrology, organized religion, outreach
• Other Emails attacks not pertaining to any other category.
Regions of Origin Defined:
Region of origin represents the percentage of messages reported coming from each of the following regions: North America, South America, Europe, Australia/Oceania, Asia and Africa.
Image spammers continue to try out new techniques – This month: PDF image spam
As fi rst reported in the May release of this report, image spam as we know it has declined
considerably over the past few months. However, image spammers have not gone away.
In May, Symantec reported that image spammers were using legitimate image upload
hosting solutions for stock spam attacks.
In June, Symantec reported an increase in spam which used links and embedded URLs to
reference images contained in spam.
In July, Symantec reports the emergence of PDF image spam. Symantec has observed at
least two variants of PDF image spam. The fi rst variant is a spam email which has a PDF attached
purporting to be a legitimate stock newsletter. This newsletter does not follow the
normal rules of images typically used in spam. For example, the newsletter looks professional
and does not contain any noise or distortions which would normally be associated
with image spam.
In the second variant, the PDF attached to the email contained a stock spam image. This
approach is very similar to image spam attacks focusing on stocks. The goal is to evade
AntiSpam fi lters which depend on being able to “read” the text of a message. This variant of
PDF image spam was targeted to over 30 million end users between the 17th June and 27th
of June 2007.
Free money anyone?
Another interesting spam attack observed this month was an attack which claimed to offer
free money to a business, “hassle-free.” The recipient was directed to call a number to
turn this “dream into a reality”. This spam email was targeted to over 32 million end users
between the 7th June and 27th of June 2007
Current affairs used to peddle medical spam
Wimbledon 2007 started June 25th and the spammer used this event to lure a recipient into
a medical spam email with a Subject: Federer and Henin top Wimbledon seeding.
As night follows day – Father’s day spam follows Mother’s day spam
Like Mother’s Day, Father’s day is celebrated on different days around the globe. Father’s
too were not forgotten by spammers this year, with spammers suggesting gift cards, online
greeting cards and even cigars for the fathers out there.
DHA attacks taken to a different level
A directory harvest attack (DHA) is an attempt to determine the valid e-mail addresses
associated with an e-mail server so that they can be added to a spam database. An e-mail
server generally returns a “Not found” reply message for all messages sent to a nonexistent
address, but does not return a message for those sent to valid addresses. The DHA program
generally creates a database of all the e-mail addresses at the server that were not returned
during the attack. Symantec recently observed a simplifi ed version of a DHA attack. Using
the premise of being a causal acquaintance, the recipient was asked if they were still at that
email address and if they could email the sender to receive an important message.
Spam spotlight: Regional spam trends APJ.
APJ Spam activity in June 2007 was overall consistent with trends observed in last month’s
report. Scams and fraud spam continued to account for 18% of all spam attacks in the Asia
Pacific and Japan (APJ) region.
Notable regionalized spam attacks include:.
Rock star recognition
One of the notable attacks this month in the APJ region is the use of famous names in
subject lines to lure the recipient into opening the spam email. In the following example a
famous pro-golfer’s name is used in the subject line.
Spam attacks continue to localize in order to target specifi c regions or countries.
As we reported in the April Symantec monthly state of spam report, we are seen increasing
amounts of spam being written to target a local region or country. The following is an
example of a work at home spam written in Japanese.