Spam continues to account for nearly 90% of the total email volume received by large enterprises, and attachment-based spam made a comeback, according to November data collected by Proofpoint, Inc. (via MediaPost).
The Proofpoint Spam Index was at 88.17% in November, indicating again that nearly 9 of 10 email messages delivered to large enterprises were spam, though down slightly from October’s index of 89.04%.
Spam base on attachments – e.g., image, PDF and Microsoft Word files – increased in November over October levels, Proofpoint found:
- Image-based spam continued to rise for the second consecutive month, increasing to 10.0% of total spam volume, up 23.8% over October.
- Microsoft Word document spam (.doc attachments) rose by 64.6% over October levels and accounted for 4.7% of total spam volume.
- Microsoft Word document spam in .rtf format also increased, accounting for 0.62% of total spam volume (a 265% increase over October levels).
- PDF spam, while still a very small percentage of total spam volume, rose to its highest levels since September: Up 101% over October levels and accounting for nearly 1.8% of total spam volume.
- MP3 spam (the spammer’s message is attached as an MP3 format audio file) declined since its debut in October, accounting for just 0.04% of total spam volume – down by 33.33%.
About the data: The Proofpoint Spam Index is a measure of the average amount of spam hitting the typical enterprise, university or government agency. The index is an average of actual spam volumes observed by Proofpoint systems deployed at a variety of customer sites, representing large organizations across a range of vertical industries, including financial services, healthcare, higher education, manufacturing and business services.
