Virus Bulletin
Copyright © 2020 Virus Bulletin
In this test – which forms part of Virus Bulletin’s continuously running security product test suite – nine full email security solutions and four blacklists of various kinds, all of which had opted to be included in our public testing, were assembled on the test bench to measure their performance against various streams of wanted, unwanted and malicious emails.
Email spam is the leading cause of malware infection. As a first line of defence, email security products have to be on full alert every day since new threats and spam techniques are constantly being developed.
The results detailed in the VBSpam test reports generally indicate that email security products are doing a good job of blocking the majority of spam emails. But in this report we will pay more attention to the emails that evaded detection and we’ll look briefly at their particularities.
The challenging times people all over the world have been going through in recent months, as well as the high level of interest in anything related to COVID-19, was reflected in spam emails. Overall, 2% of the spam emails we saw in the test contained the words ‘covid’ or ‘coronavirus’ either in the subject or in the text of the email. The number of these emails decreased gradually after peaking at the beginning of the test (for the first three days of the test 6% of spam emails daily contained such a reference). The good news is that the majority of these emails were blocked by the security products we tested. Screenshots below show some examples of the COVID-19 related emails that we saw.
Examples of the COVID-19 related emails seen during the test.
For some additional background to this report, the table and map below show the geographical distribution (based on sender IP address) of the spam emails seen in the test. (Note: these statistics are relevant only to the spam samples we received in real time and shouldn’t be seen as attribution of intent.)
| # | Sender's IP country | Percentage of spam |
| 1 | China | 19.42% |
| 2 | Japan | 19.27% |
| 3 | United States | 11.77% |
| 4 | Russian Federation | 5.57% |
| 5 | Vietnam | 3.52% |
| 6 | Brazil | 3.52% |
| 7 | Germany | 2.65% |
| 8 | Ukraine | 2.15% |
| 9 | India | 1.72% |
| 10 | Indonesia | 1.45% |
Top 10 countries from which spam was sent.
Geographical distribution of spam based on sender IP address.
In this test we continue to highlight the email security solutions’ performance against malware and phishing emails. In these two categories we consider emails with a malicious attachment or containing links that either lead to a site with a fake login page (traditional phishing) or that download malware. Also considered as phishing are those emails with an HTML or PDF attachment that doesn’t display malicious behaviour itself, but which contains links that lead to a phishing site.
The following are some of the most challenging malware and phishing emails we saw in the test.
Example of a Zloader malicious email.
Screenshot of the malicious XLS file when first opened.
Spyware email.
Trojan banker email.
Phishing email.
Netflix phishing email.
Spam catch rates continued to be high, with the majority of products blocking more than 99% of the spam, but the catch rates on malware and phishing were significantly lower.
Four of the participating full solutions achieved a VBSpam award, while two – Bitdefender and Fortinet – performed well enough to achieve a VBSpam+ award.
SC rate: 98.68%
FP rate: 0.52%
Final score: 95.86
Malware catch rate: 96.72%
Phishing catch rate: 95.60%
Project Honey Pot SC rate: 99.09%
Abusix SC rate: 98.49%
Newsletters FP rate: 8.3%
Speed:
| 10% |  |
50% | |
95% | |
98% | |
SC rate: 99.43%
FP rate: 0.00%
Final score: 99.43
Malware catch rate: 93.71%
Phishing catch rate: 97.07%
Project Honey Pot SC rate: 99.81%
Abusix SC rate: 99.26%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 99.76%
FP rate: 0.00%
Final score: 99.76
Malware catch rate: 96.07%
Phishing catch rate: 98.22%
Project Honey Pot SC rate: 99.98%
Abusix SC rate: 99.66%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 99.84%
FP rate: 0.00%
Final score: 99.84
Malware catch rate: 98.43%
Phishing catch rate: 98.01%
Project Honey Pot SC rate: 99.94%
Abusix SC rate: 99.79%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 99.53%
FP rate: 0.02%
Final score: 99.45
Malware catch rate: 99.08%
Phishing catch rate: 98.32%
Project Honey Pot SC rate: 99.94%
Abusix SC rate: 99.34%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 99.62%
FP rate: 0.02%
Final score: 99.54
Malware catch rate: 99.74%
Phishing catch rate: 99.58%
Project Honey Pot SC rate: 99.98%
Abusix SC rate: 99.45%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% |  |
SC rate: 95.58%
FP rate: 0.02%
Final score: 95.50
Malware catch rate: 92.01%
Phishing catch rate: 83.35%
Project Honey Pot SC rate: 99.25%
Abusix SC rate: 93.89%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 93.54%
FP rate: 0.00%
Final score: 93.54
Malware catch rate: 86.37%
Phishing catch rate: 73.93%
Project Honey Pot SC rate: 98.48%
Abusix SC rate: 91.26%
Newsletters FP rate: 0.0%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 98.48%
FP rate: 0.00%
Final score: 98.45
Malware catch rate: 99.21%
Phishing catch rate: 98.22%
Project Honey Pot SC rate: 99.96%
Abusix SC rate: 97.80%
Newsletters FP rate: 1.3%
Speed:
| 10% | |
50% | |
95% | |
98% | |
SC rate: 98.72%
FP rate: 0.13%
Final score: 98.06
Malware catch rate: 93.45%
Phishing catch rate: 95.29%
Project Honey Pot SC rate: 98.58%
Abusix SC rate: 98.78%
Newsletters FP rate: 0.0%
SC rate: 94.35%
FP rate: 0.00%
Final score: 94.35
Malware catch rate: 86.63%
Phishing catch rate: 80.31%
Project Honey Pot SC rate: 99.35%
Abusix SC rate: 92.04%
Newsletters FP rate: 0.0%
SC rate: 92.12%
FP rate: 0.00%
Final score: 92.12
Malware catch rate: 85.98%
Phishing catch rate: 74.87%
Project Honey Pot SC rate: 98.55%
Abusix SC rate: 89.17%
Newsletters FP rate: 0.0%
SC rate: 61.96%
FP rate: 0.00%
Final score: 61.96
Malware catch rate: 5.77%
Phishing catch rate: 30.68%
Project Honey Pot SC rate: 93.76%
Abusix SC rate: 47.32%
Newsletters FP rate: 0.0%
| True negatives | False positives | FP rate | False negatives | True positives | SC rate | Final score | VBSpam | |
| Abusix Mail Intelligence rspamd | 6031 | 74 | 0.52% | 1538 | 115135.6 | 98.68% | 95.86 | |
| Axway | 6105 | 0 | 0.00% | 663 | 116010.6 | 99.43% | 99.43 |  |
| Bitdefender | 6105 | 0 | 0.00% | 277.2 | 116396.4 | 99.76% | 99.76 |  |
| FortiMail | 6105 | 0 | 0.00% | 188.4 | 116485.2 | 99.84% | 99.84 | |
| IBM | 6104 | 1 | 0.02% | 546.8 | 116126.8 | 99.53% | 99.45 | |
| Libraesva | 6104 | 1 | 0.02% | 443 | 116230.6 | 99.62% | 99.54 | |
| Spamhaus DQS | 6104 | 1 | 0.02% | 5157.2 | 111516.4 | 95.58% | 95.50 | |
| Spamhaus rsync | 6105 | 0 | 0.00% | 7537.4 | 109136.2 | 93.54% | 93.54 | |
| ZEROSPAM | 6105 | 0 | 0.00% | 1775 | 114888.6 | 98.48% | 98.45 | |
| Abusix Mail Intelligence* | 6056 | 49 | 0.13% | 1499.2 | 115174.4 | 98.72% | 98.06 | N/A |
| IBM X-Force Combined* | 6105 | 0 | 0.00% | 6597.8 | 110075.8 | 94.35% | 94.35 | N/A |
| IBM X-Force IP* | 6105 | 0 | 0.00% | 9188.2 | 107485.4 | 92.12% | 92.12 | N/A |
| IBM X-Force URL* | 6105 | 0 | 0.00% | 44378.6 | 72295 | 61.96% | 61.96 | N/A |
*These products are partial solutions and their performance should not be compared with that of other products.
(Please refer to the text for full product names and details.)
| Newsletters | Malware | Phishing | Project Honey Pot | Abusix | STDev† | ||||||
| False positives | FP rate | False negatives | SC rate | False negatives | SC rate | False negatives | SC rate | False negatives | SC rate | ||
| Abusix Mail Intelligence rspamd | 13 | 8.3% | 25 | 96.72% | 42 | 95.60% | 334.4 | 99.09% | 1203.6 | 98.49% | 1.39 |
| Axway | 0 | 0.0% | 48 | 93.71% | 28 | 97.07% | 70.6 | 99.81% | 592.4 | 99.26% | 0.88 |
| Bitdefender | 0 | 0.0% | 30 | 96.07% | 17 | 98.22% | 6 | 99.98% | 271.2 | 99.66% | 0.63 |
| FortiMail | 0 | 0.0% | 12 | 98.43% | 19 | 98.01% | 21.2 | 99.94% | 167.2 | 99.79% | 0.42 |
| IBM | 0 | 0.0% | 7 | 99.08% | 16 | 98.32% | 21 | 99.94% | 525.8 | 99.34% | 2.7 |
| Libraesva | 0 | 0.0% | 2 | 99.74% | 4 | 99.58% | 7 | 99.98% | 436 | 99.45% | 0.61 |
| Spamhaus DQS | 0 | 0.0% | 61 | 92.01% | 159 | 83.35% | 276.6 | 99.25% | 4880.6 | 93.89% | 3.8.5 |
| Spamhaus rsync | 0 | 0.0% | 104 | 86.37% | 249 | 73.93% | 560 | 98.48% | 6977.4 | 91.26% | 5.62 |
| ZEROSPAM | 2 | 1.3% | 6 | 99.21% | 17 | 98.22% | 14 | 99.96% | 1761 | 97.80% | 1.83 |
| Abusix Mail Intelligence* | 0 | 0.0% | 50 | 93.45% | 45 | 95.29% | 522.2 | 98.58% | 977 | 98.78% | 1.7 |
| IBM X-Force Combined* | 0 | 0.0% | 102 | 86.63% | 188 | 80.31% | 240.2 | 99.35% | 6357.6 | 92.04% | 5.08 |
| IBM X-Force IP* | 0 | 0.0% | 107 | 85.98% | 240 | 74.87% | 534 | 98.55% | 8654.2 | 89.17% | 5.54 |
| IBM X-Force URL* | 0 | 0.0% | 719 | 5.77% | 662 | 30.68% | 2297.6 | 93.76% | 42081 | 47.32% | 12.06 |
*These products are partial solutions and their performance should not be compared with that of other products. None of the queries to the IP blacklists included any information on the attachments; hence their performance on the malware corpus is added purely for information.
† The standard deviation of a product is calculated using the set of its hourly spam catch rates.
(Please refer to the text for full product names and details.)
| Speed | ||||
| 10% | 50% | 95% | 98% | |
| Abusix Mail Intelligence rspamd | |
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| Axway | |
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| Bitdefender | |
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| FortiMail | |
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| IBM | |
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| Libraesva | |
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| Spamhaus DQS | |
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| ZEROSPAM | |
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(Please refer to the text for full product names and details.)
|
0-30 seconds | |
30 seconds to two minutes |  |
two minutes to 10 minutes |  |
more than 10 minutes |
| Products ranked by final score | |
| FortiMail | 99.84 |
| Bitdefender | 99.76 |
| Libraesva | 99.54 |
| IBM | 99.45 |
| Axway | 99.43 |
| ZEROSPAM | 98.45 |
| Abusix Mail Intelligence rspamd | 95.86 |
| Spamhaus DQS | 95.50 |
| Spamhaus rsync | 93.54 |
(Please refer to the text for full product names and details.)
| Hosted solutions | Anti-malware | IPv6 | DKIM | SPF | DMARC | Multiple MX-records | Multiple locations |
| ZEROSPAM | ClamAV | √ | √ | √ | √ | √ |
(Please refer to the text for full product names and details.)
| Local solutions | Anti-malware | IPv6 | DKIM | SPF | DMARC | Interface | |||
| CLI | GUI | Web GUI | API | ||||||
| Axway | Kaspersky, McAfee | √ | √ | √ | √ | ||||
| Bitdefender | Bitdefender | √ | √ | √ | √ | ||||
| FortiMail | Fortinet | √ | √ | √ | √ | √ | √ | √ | |
| IBM | Sophos; IBM Remote Malware Detection | √ | √ | √ | |||||
| Libraesva | ClamAV; others optional | √ | √ | √ | √ | ||||
| Spamhaus DQS | Optional | √ | √ | √ | √ | ||||
| Spamhaus rsync | Optional | √ | √ | √ | √ | ||||
(Please refer to the text for full product names and details.)
(Please refer to the text for full product names and details.)
The full VBSpam test methodology can be found at https://www.virusbulletin.com/testing/vbspam/vbspam-methodology/vbspam-methodology-ver20.
The test ran for 16 days, from 12am on 9 May to 12am on 25 May 2020.
The test corpus consisted of 123,158 emails. 116,896 of these were spam, 36,825 of which were provided by Project Honey Pot, with the remaining 80,071 spam emails provided by Abusix. There were 6,105 legitimate emails (‘ham’) and 157 newsletters, a category that includes various kinds of commercial and non-commercial opt-in mailings.
278 emails in the spam corpus were considered ‘unwanted’ (see the June 2018 report1) and were included with a weight of 0.2; this explains the non-integer numbers in some of the tables.
Moreover, 763 emails from the spam corpus were found to contain a malicious attachment while 955 contained a link to a phishing or malware site; though we report separate performance metrics on these corpora, it should be noted that these emails were also counted as part of the spam corpus.
Emails were sent to the products in real time and in parallel. Though products received the email from a fixed IP address, all products had been set up to read the original sender’s IP address as well as the EHLO/HELO domain sent during the SMTP transaction, either from the email headers or through an optional XCLIENT SMTP command2.
For those products running in our lab, we all ran them as virtual machines on a VMware ESXi cluster. As different products have different hardware requirements – not to mention those running on their own hardware, or those running in the cloud – there is little point comparing the memory, processing power or hardware the products were provided with; we followed the developers’ requirements and note that the amount of email we receive is representative of that received by a small organization.
Although we stress that different customers have different needs and priorities, and thus different preferences when it comes to the ideal ratio of false positives to false negatives, we created a one-dimensional 'final score' to compare products. This is defined as the spam catch (SC) rate minus five times the weighted false positive (WFP) rate. The WFP rate is defined as the false positive rate of the ham and newsletter corpora taken together, with emails from the latter corpus having a weight of 0.2:
WFP rate = (#false positives + 0.2 * min(#newsletter false positives , 0.2 * #newsletters)) / (#ham + 0.2 * #newsletters)
while in the spam catch rate (SC), emails considered ‘unwanted’ (see above) are included with a weight of 0.2.
The final score is then defined as:
Final score = SC - (5 x WFP)
In addition, for each product, we measure how long it takes to deliver emails from the ham corpus (excluding false positives) and, after ordering these emails by this time, we colour-code the emails at the 10th, 50th, 95th and 98th percentiles:
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(green) = up to 30 seconds |
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(yellow) = 30 seconds to two minutes |
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(orange) = two to ten minutes |
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(red) = more than ten minutes |
Products earn VBSpam certification if the value of the final score is at least 98 and the ‘delivery speed colours’ at 10 and 50 per cent are green or yellow and that at 95 per cent is green, yellow or orange.
Meanwhile, products that combine a spam catch rate of 99.5% or higher with a lack of false positives, no more than 2.5% false positives among the newsletters and ‘delivery speed colours’ of green at 10 and 50 per cent and green or yellow at 95 and 98 per cent earn a VBSpam+ award.
1 https://www.virusbulletin.com/virusbulletin/2018/06/vbspam-comparative-review.
