Did you just stumble upon a download or a file on your computer that has a digital signature from middle pages? Some of the security products refers to the detected files as Adware.BrowseFox.AL and Generic.F31. The detection rate for the middle pages files collected here is 38%. Please read on for more details.
You'll probably see middle pages when double-clicking to run the file. The publisher name shows up as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view the additional details from the middle pages digital signature with the following procedure:
Here's a screenshot of a file that has been signed by middle pages:

As you can see in the screencap above, Windows reports that "This digital signature is OK". This means that the file has been published by middle pages and that the file has not been tampered with.
If you click the View Certificate button shown in the screenshot above, you can examine all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, etc. You can also examine the address for middle pages, such as the street name, city and country.
VeriSign Class 3 Code Signing 2010 CA has issued the middle pages certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the middle pages files I've gathered, thanks to the FreeFixer users.
Here's the detection names for the middle pages files. I've grouped the detection names by each scanner engine. Thanks to VirusTotal for the scan results.
| Scanner | Detection Names |
|---|---|
| ALYac | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| AVG | Generic.F31, BrowseFox.F |
| AVware | Trojan.Win32.Generic!BT, Yontoo (fs) |
| Ad-Aware | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| Agnitum | Riskware.Agent!, PUA.BrowseFox! |
| AhnLab-V3 | PUP/Win32.SwiftBrowse |
| Antiy-AVL | GrayWare[AdWare:not-a-virus,HEUR]/Win32.Kranet |
| Avast | NSIS:BrowseFox-D [PUP], Win32:BrowseFox-EC [PUP] |
| Avira | Adware/BrowseFox.A.15, ADWARE/BrowseFox.Gen7, Adware/BrowseFox.A.1227, ADWARE/BrowseFox.Gen2 |
| Baidu-International | Adware.Win64.BrowseFox.bCG, Adware.Win32.BrowseFox.BC, Adware.MSIL.BrowseFox.BH, Adware.Win64.BrowseFox.BCG |
| BitDefender | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| ClamAV | Win.Adware.Swiftbrowse-497, Win.Adware.Netfilter-130, Win.Adware.Netfilter-134, Win.Adware.Swiftbrowse-717 |
| Comodo | TrojWare.Win32.AltBrowse.IZZV, Application.Win32.BrowseFox.JM, Application.Win32.AltBrowse.ZPGI |
| DrWeb | Tool.NetFilter.313, Trojan.BPlug.123, Trojan.BPlug.215, Trojan.BPlug.303 |
| ESET-NOD32 | a variant of Win64/BrowseFox.CG, Win32/BrowseFox.C, a variant of MSIL/BrowseFox.H, a variant of Win32/BrowseFox.O, a variant of Win32/BrowseFox.J |
| Emsisoft | Adware.SwiftBrowse.CH (B), Adware.BrowseFox.V (B), Adware.BrowseFox.AL (B) |
| F-Prot | W64/A-59c9c70a!Eldorado, W32/A-b3b70cb0!Eldorado, W32/A-76f53fd6!Eldorado |
| F-Secure | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| Fortinet | Adware/BrowseFox |
| GData | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| Ikarus | PUA.BrowseFox |
| K7AntiVirus | Unwanted-Program ( 0040f9881 ), Trojan ( 0040f9921 ), Trojan ( 004a07971 ), Adware ( 700000121 ) |
| K7GW | Unwanted-Program ( 0040f9881 ), Trojan ( 0040f9921 ), Trojan ( 004a07971 ), Adware ( 700000121 ) |
| Kaspersky | not-a-virus:HEUR:AdWare.Win32.Kranet.heur |
| Malwarebytes | PUP.Optional.HoldPage.A |
| McAfee | Artemis!B86DBA10C76D, Artemis!F565FA82539E, Artemis!DCDA1662B2BC, Artemis!9E31D54B68F8 |
| McAfee-GW-Edition | Artemis |
| MicroWorld-eScan | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
| NANO-Antivirus | Riskware.Win32.NetFilter.dgqvkd, Riskware.Win32.NetFilter.dgkdox, Trojan.Win32.BPlug.dfogbn, Riskware.Win32.Kranet.dgxoam |
| Qihoo-360 | HEUR/QVM42.0.Malware.Gen, Win32/Virus.Adware.708, HEUR/QVM10.1.Malware.Gen, HEUR/QVM03.0.Malware.Gen |
| Sophos | Generic PUA AK |
| Symantec | Yontoo.C |
| TrendMicro-HouseCall | Suspicious_GEN.F47V1208, Suspicious_GEN.F47V1211 |
| VBA32 | AdWare.Win64.Yotoon, AdWare.SwiftBrowse, AdWare.LinkSwift |
| VIPRE | Trojan.Win32.Generic!BT, Yontoo (fs) |
| Zillya | Adware.Yotoon.Win64.14, Adware.Yotoon.Win64.10, Backdoor.CPEX.Win32.29350, Backdoor.PePatch.Win32.52828 |
| nProtect | Adware.SwiftBrowse.CH, Adware.NetFilter.J, Adware.BrowseFox.V, Adware.BrowseFox.AL |
The detection percentage is based on the fact that I've gathered 1616 scan results for the middle pages files. 616 of these scan reports came up with some sort of detection. You can review 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: