ICAP Header Responses Parent topic

For each sample submitted by ICAP clients, Deep Discovery Analyzer returns ICAP headers.
The following shows an example.
ICAP/1.0 200 OK
Server: Deep Discovery Analyzer 6.8 Build 1165
ISTag: "12.300.1011"
X-Virus-ID: TROJ_FRS.0NA103DD20,TROJ_FRS.0NA104DD20 
X-Infection-Found: Type=0; Resolution=2; Threat=TROJ_FRS.0NA103
DD20,TROJ_FRS.0NA104DD20;
X-Response-Desc: URL: No risk rating from WRS; FILE: Detected b
y ATSE
Encapsulated: res-hdr=0, res-body=86
Date: Thu, 16 Apr 2020 07:38:01 GMT
The following table describes the ICAP headers.
ICAP Headers
Values
Examples
ICAP/1.0
ICAP status code.
For example:
  • 204: If an ICAP client accepts the 204 status code with cached content
  • 200:
    • If an ICAP client does not accept the 204 status code
    • Content is too big for an ICAP client to store in the cache. Deep Discovery Analyzer will return 200 OK with the HTTP content.
    • A threat is detected. Deep Discovery Analyzer will return 200 OK with the ICAP header and HTTP 403 Forbidden
For more information on the status codes, see the RFC documentation.
ICAP 1.0 200 OK
ICAP 1.0 204 No Content
Server
Deep Discovery Analyzer version and build number
Server: Deep Discovery Analyzer 6.8 Build 1165
ISTag
Version of the Advanced Threat Scan Engine for Deep Discovery (Linux, 64-bit) component
This is used to validate that previous Deep Discovery Analyzer responses can still be considered fresh by an ICAP client that may still be caching them.
ISTag: "12.300.1011"
Encapsulated
The offset of each encapsulated section's start relative to the start of the encapsulating message's body
Encapsulated: req-hdr=0, req-body=86
Date
The date time value provided by the Deep Discovery Analyzer clock, specified as an RFC 1123 compliant date/time string
Date: Thu, 16 Apr 2020 07:38:01 GMT
For more details about ICAP headers, refer to the following site:
The following table describes the additional headers that Deep Discovery Analyzer returns.
Note
Note
If enabled, Deep Discovery Analyzer always returns the X-Response-Desc header, and only returns the X-Virus-ID and X-Infection-Found headers when a known threat is detected during the pre-scanning of samples received from ICAP clients.
ICAP Headers
Values
Examples
X-Virus-ID
One line of US-ASCII text with the name of the virus or risk encountered
X-Virus-ID: TSPY_ONLINEG.MCS
X-Infection-Found
Numeric code for the type of infection, the resolution, and the risk description
X-Infection-Found: Type=0; Resolution=2; Threat=TSPY_ONLINEG.MCS;
X-Response-Desc
Reason Deep Discovery Analyzer considers a URL or file sample as malicious or safe
X-Response-Desc: URL: No risk rating from WRS; FILE: Detected by ATSE
Note
Note
To enable these headers and configure other ICAP settings, go to AdministrationIntegrated Products/Services ICAP.
For details, see Configuring ICAP Settings.
The X-Response-Desc header varies based on the pre-scan result. The following tables describes the X-Response-Desc headers.

X-Response-Desc headers: URL

X-Response-Desc Header
Description
No risk rating from WRS
The URL is detected by Web Reputation Services (WRS) and is considered as safe.
Match found in URL exception list
The URL matches an entry in the exception list and is displayed on the Exceptions screen.
No risk rating from VA
The URL is detected by Virtual Analyzer is considered as safe.
Bypass URL scanning in RESPMOD mode
If you select Bypass URL scanning in RESPMOD mode on the ICAP screen, Deep Discovery Analyzer does not scan URLs in RESPMOD mode.
Invalid URL
The URL is detected with an invalid format.
Unable to analyze URL in VA
The URL is not supported in Virtual Analyzer.
Detected by WRS
The URL is detected by WRS and is considered as malicious.
Detected by suspicious objects list
The URL matches an entry in the suspicious objects list.
Detected by user-defined suspicious objects list
The URL matches an entry in the user-defined suspicious objects list.
Detected by VA cache
The URL is already analyzed by Virtual Analyzer and is considered as malicious.
URL submitted to VA
No pre-scan result is available for the URL. Submit the URL sample to Virtual Analyzer for analysis.

X-Response-Desc headers: File

X-Response-Desc Header
Description
Match found in file exception list
The file matches an entry in the exception list and is displayed on the Exceptions screen.
No risk rating from VA
The file is detected by Virtual Analyzer is considered as safe.
Unsupported file type in VA
The file is not analyzed by Virtual Analyzer due to one of the following:
  • The file type is not supported in Virtual Analyzer
    For more information on supported file types, see Submission Settings Tab.
  • The file is password protected and cannot be extracted by Virtual Analyzer for analysis
  • Other reasons that Virtual Analyzer is unable to perform the file analysis
Bypass MIME content-type scanning
If you select Enable MIME content-type exclusion and the content-type is in the exclusion list, Deep Discovery Analyzer does not scan the file.
Maximum file size exceeded
The file size has exceeded the maximum (60MB).
Bypass true file type scanning
If you select Enable MIME content-type validation and the file type is in the exclusion list, Deep Discovery Analyzer does not scan the file.
Detected by ATSE
The file is detected by Advanced Threat Scan Engine (ATSE) for Deep Discovery.
Detected by YARA rule
The file matches a YARA rule.
Detected by suspicious objects list
The file matches an entry in the suspicious objects list.
Detected by user-defined suspicious objects list
The file matches an entry in the user-defined suspicious objects list.
Detected by Predictive Machine Learning engine
The file is detected by the Predictive Machine Learning engine.
Detected by VA cache
The file is already analyzed by Virtual Analyzer and is considered as malicious.
File submitted to VA
No pre-scan result is available for the file. Submit the file sample to Virtual Analyzer for analysis.
The following header example indicates that the file and URL are considered safe.
ICAP/1.0 204 No Content
Server: Deep Discovery Analyzer 6.8 Build 1165
ISTag: "12.300.1011"
X-Response-Desc: URL: No risk rating from WRS; FILE: No risk ra
ting from VA
Date: Thu, 16 Apr 2020 07:32:30 GMT
The following header example indicates that Deep Discovery Analyzer returns the HTTP/1.1 403 Forbidden status code because the file is detected by ATSE. The URL is not scanned.
Note
Note
If you configure the redirect page in the management console, Deep Discovery Analyzer sends the redirect page content after the HTTP 403 Forbidden header.
ICAP/1.0 200 OK
Server: Deep Discovery Analyzer 6.8 Build 1165
ISTag: "12.300.1011"
X-Virus-ID: TROJ_FRS.0NA103DD20,TROJ_FRS.0NA104DD20 
X-Infection-Found: Type=0; Resolution=2; Threat=TROJ_FRS.0NA103
DD20,TROJ_FRS.0NA104DD20;
X-Response-Desc: URL: Bypass URL scanning in RESPMOD mode; FILE
: Detected by ATSE
Encapsulated: res-hdr=0, res-body=86
Date: Thu, 16 Apr 2020 07:38:01 GMT

HTTP/1.1 403 Forbidden
The following header example indicates that the URL is considered as safe and there is no detection information for the file. The file sample is automatically submitted to Deep Discovery Analyzer for analysis.
ICAP/1.0 204 No Content
Server: Deep Discovery Analyzer 6.8 Build 1165
ISTag: "12.300.1011"
X-Response-Desc: URL: No risk rating from WRS; FILE: File submi
tted to VA
Date: Thu, 16 Apr 2020 07:22:41 GMT