Method and system for transparently manipulating downloaded files

A computer-usable non-transitory storage medium having a computer program embodied thereon for causing a suitable programmed system to manipulate a computer file, by performing the following steps when such program is executed on the system, the steps comprising:

• receiving a response including a file download request from a client computer and obtaining Hypertext Transport Protocol (HTTP) headers of the file download request;
• downloading the file associated with the file download request, canceling the file download request, and associating the downloaded file with an indicator, and, maintaining the downloaded file to prevent leaking of the downloaded file from a computerized inspection device;
• transmitting a redirect request including an indicator of the redirect request, the redirect request associated with the downloaded file and the indicator associated with the downloaded file, to a client computer;
• receiving from the client computer, the redirect request;
• correlating the indicator of the redirect request and the indictor associated with the downloaded file, by matching the indicator of the redirect request and the indictor associated with the downloaded file;
• inspecting the downloaded file, by the computerized inspection device, to determine whether the downloaded file is to be modified;
• performing at least one of modifying or not modifying the downloaded file based on the determination;
• and
• transmitting the downloaded file, as one of either modified or not modified, to the client computer, when the indicator of the redirect request and the indicator associated with the downloaded file are correlated.

A computerized inspection device comprising:

• storage media for holding downloaded files;
• and
• a processor in communication with the storage media, the processor programmed to:
• receive a response including a file download request issued from a client computer, which has passed through the computerized inspection device, and obtain Hypertext Transport Protocol (HTTP) headers of the file download request;
• download the file associated with the download request for storage in the storage media, and canceling the file download request, and, associate the downloaded file with an indicator;
• cause the storage media to maintain the downloaded file by preventing leaking of the downloaded file from the storage media;
• transmit a redirect request including an indicator of the redirect request, the redirect request associated with the downloaded file and the indicator associated with the downloaded file, to the client computer;
• receive, from the client computer, the redirect request;
• correlate the indicator of the redirect request and the indictor associated with the downloaded file, by matching the indicator of the redirect request and the indictor associated with the downloaded file;
• inspect the downloaded file, by the computerized inspection device, to determine whether the downloaded file is to be modified;
• perform at least one of modifying or not modifying the file based on the determination;
• and
• transmitting the downloaded file, as one of either modified or not modified, to the client computer, when the indicator of the redirect request and the indicator associated with the downloaded file are correlated.