Last week I wrote about 3 million
fake YouTube pages leading to fake antivirus pages. The day after the blog was published, they seemed to be gone from the Google index, as search results were showing only 2 to 4 of the malicious pages. But now...they are back again.
After my last post, some questioned whether or not there were actually 3 million fake YouTube pages in the google index. In fact, Google contacted me to suggest that there were only 77 results. I disagree. Why isn't the total number of results straight forward? Although Google's search results may state that approximately 3 million results exist, the search engine won't actually deliver that number of raw results. Given that fact, how can we know the total number of pages currently indexed by Google for a particular query? Only Google know the exact number, but by issuing various different types of queries, we can make a reasonable estimate.
Attempt to get all pages
Since all the pages contain "page.php?page=" in the URL, and "Hot Video" in the title, we can try a single query to find all of them with:
inurl:"page.php?page=" "hot video"
The Google search results currently show "
About 2,990,000 results" (the number varied between 2.8 million and .4 million), but there are only 8 pages of results (90 links) shared, or 12 pages (121 links) if we click on "
repeat the search with the omitted results included".
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| 3 million fake YouTube pages? |
It may look like Google has indexed "only" 121 fake "Hot Video" pages (despite suggesting ~3 million results), but other queries paint a different picture.
Domain query
Let's take the first domain hosting malicious pages from the first query:
addisonhouse.com.
To find out the number of fake YouTube pages hosted by this domain, we can try the following query:
site:addisonhouse.com "hot video"
Google states that there are "
About 7,850 results" but actually shares 51 pages of results (512 links).
For the domain
memoryshack.net, Google indicates "
About 204 results" and provides a total of 204 links for this search. For the domain
theochristi.com, I get 245 results, etc.
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| "Hot Video" pages hosted on addisonhouse.com |
A first estimate
An initial estimate can be obtained by multiplying the number of domains seen in the first query by an average of 250 pages. This gives an estimate of the minimum number of pages in Google's index. The real number is very likely much higher.
The 90 results form the first query show 90 different domains. This means there are at least 90 * 250 =
22,500 pages.
Many more domains
Are there only 90 domains infected with "Hot Video" pages as the first query suggested? Unfortunately, there are many more. Fake pages are being created for each search term found in
Google Hot Trends.
For example, I checked a search that was popular 6 days ago:
erica blasberg "hot video". On page 2, I found a fake YouTube page on a domain that is not listed in the first query:
elijasalud.com.
On page 3 of the results, there is another domain not seen in the first query:
sklep.aicom.com.pl.
etc.
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| New domain infected shown for a different search |
Google has clearly indexed more than 90 infected domains, but it remains difficult to know the exact number.
How many could there be?
Attackers create one "Hot Video" pages for each popular search as shown in
Google Hot Trends. There are 20 hot searches each day, but one search can be popular for several days. I've checked a few infected domains, and found pages created for searches popular on June 1st. So there are pages for at latest 90 days of popular trends on each domain.
That gives us 90 * 20 = 1,800 pages. Assuming that a few search terms that are popular over several days, we can use an estimate of
1,500 pages per domain. If Google indexed (only) 100 of these domains, that would be 150,000 fake Video pages.
Only Google knows the exact number of infected domains indexed, and the total number of malicious pages. We estimate that they have at the very least , 22,500 such malicious pages in their index. The number of 3 millions "Hot Video" page is not however inconceivable. It means Google would have indexed:
- 2,000 infected domains with 90 days worth of Google Hot Trends
- or 1,250 infected domains with 120 days worth of Google Hot Trends
"Hot Video" in action
Here is a video of a user browsing a "Hot Video" page, and being redirected to a fake AV page. Then I uploaded the malicious executable to VirusTotal - sadly, only
20% of the antivirus vendors detect the malware.
-- Julien