I found the following interesting traffic in my apache log:
213.159.213.236 - - [16/Dec/2019:03:02:03 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0.7.01001)"
213.159.213.236 - - [16/Dec/2019:03:02:19 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0.7.01001)"
213.159.213.236 - - [16/Dec/2019:03:02:25 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36"
213.159.213.236 - - [16/Dec/2019:03:02:40 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"
213.159.213.236 - - [16/Dec/2019:03:02:48 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; MSIE 5.5; Windows NT 5.0) Opera 7.02 Bork-edition [en]"
213.159.213.236 - - [16/Dec/2019:03:03:06 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.2.8) Gecko/20100723 Ubuntu/10.04 (lucid) Firefox/3.6.8"
213.159.213.236 - - [16/Dec/2019:03:04:22 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0.7.01001)"
213.159.213.236 - - [16/Dec/2019:03:04:36 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)"
213.159.213.236 - - [16/Dec/2019:03:04:51 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_2) AppleWebKit/601.3.9 (KHTML, like Gecko) Version/9.0.2 Safari/601.3.9"
213.159.213.236 - - [16/Dec/2019:03:05:06 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0"
213.159.213.236 - - [16/Dec/2019:03:05:26 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36 Edge/12.246"
213.159.213.236 - - [16/Dec/2019:03:05:37 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36"
213.159.213.236 - - [16/Dec/2019:03:07:23 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; MSIE 5.5; Windows NT 5.0) Opera 7.02 Bork-edition [en]"
213.159.213.236 - - [16/Dec/2019:03:07:37 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; MSIE 5.5; Windows NT 5.0) Opera 7.02 Bork-edition [en]"
213.159.213.236 - - [16/Dec/2019:03:07:57 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/5.0 (X11; CrOS x86_64 8172.45.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.64 Safari/537.36"
213.159.213.236 - - [16/Dec/2019:03:08:07 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"
213.159.213.236 - - [16/Dec/2019:03:08:22 -0500] "GET / HTTP/1.1" 200 3797 "-" "Opera/9.80 (Windows NT 5.1; U; en) Presto/2.10.289 Version/12.01"
213.159.213.236 - - [16/Dec/2019:03:08:26 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"
213.159.213.236 - - [16/Dec/2019:03:09:13 -0500] "GET / HTTP/1.1" 200 3797 "-" "Opera/9.80 (Windows NT 5.1; U; en) Presto/2.10.289 Version/12.01"
213.159.213.236 - - [16/Dec/2019:03:09:24 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)"
213.159.213.236 - - [16/Dec/2019:03:09:35 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0.7.01001)"
What is the point of this? What is this attacker trying to accomplish by pretending to run Bork edition of Opera from 2003, or still using Firefox 3.6 on Ubuntu 10.04? Is it simply to poison any site statistics I might have on my visitors? If so, wouldn't it make sense to spoof a more likely user agent, like IE 8.0...?
I'm hoping for any insights you might have.