Did you just run into a download or a file on your computer that has been digitally signed by Beijing Sogou Information Service Co., Ltd.? Some of the security products refers to the detected files as Adware.Sogou and RiskWare[Downloader]/Win32.Sogou.g. The detection rate for the Beijing Sogou Information Service Co., Ltd. files collected here is 4%. Please read on for more details.
You will probably see Beijing Sogou Information Service Co., Ltd. when running the file. The publisher name shows up as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view additional details from the Beijing Sogou Information Service Co., Ltd. certificate with the following procedure:
Here's a screengrab of a file signed by Beijing Sogou Information Service Co., Ltd.:

As you can see in the screenshot above, Windows states that "This digital signature is OK". This means that the file has been published by Beijing Sogou Information Service Co., Ltd. and that the file has not been tampered with.
If you click the View Certificate button shown in the screenshot above, you can view all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, and so on. You can also view the address for Beijing Sogou Information Service Co., Ltd., such as the street name, city and country.
Symantec Class 3 SHA256 Code Signing CA and VeriSign Class 3 Code Signing 2010 CA has issued the Beijing Sogou Information Service Co., Ltd. certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screencap above.
These are the Beijing Sogou Information Service Co., Ltd. files I have collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 8/57 | IEHint.dll |
| 0/53 | OmniAddr.dll |
| 0/56 | updateservice.exe |
| 0/56 | IEHint64.dll |
Here's the detection names for the Beijing Sogou Information Service Co., Ltd. files. I have grouped the detection names by each scanner engine. Thanks to VirusTotal for the scan results.
| Scanner | Detection Names |
|---|---|
| AVG | Generic.537 |
| AVware | Adware.Sogou |
| Antiy-AVL | RiskWare[Downloader]/Win32.Sogou.g |
| Fortinet | Riskware/Sogou |
| Kaspersky | not-a-virus:Downloader.Win32.Sogou.g |
| Panda | Generic Suspicious |
| VBA32 | Downloader.Sogou |
| VIPRE | Adware.Sogou |
The detection percentage is based on the fact that I've collected 222 scan results for the Beijing Sogou Information Service Co., Ltd. files. 8 of these scan reports came up with some sort of detection. You can view the full details of the scan reports by examining the files listed above.
The analysis has been done on certificates with the following serial numbers: