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CLAMD.CONF(5) - man page online | file formats

Configuration file for Clam AntiVirus Daemon.

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December 4, 2013
clamd.conf(5)                             Clam AntiVirus                            clamd.conf(5)

NAME clamd.conf - Configuration file for Clam AntiVirus Daemon
DESCRIPTION clamd.conf configures the Clam AntiVirus daemon, clamd(8).
FILE FORMAT The file consists of comments and options with arguments. Each line which starts with a hash (#) symbol is ignored by the parser. Options and arguments are case sensitive and of the form Option Argument. The arguments are of the following types: BOOL Boolean value (yes/no or true/false or 1/0). STRING String without blank characters. SIZE Size in bytes. You can use 'M' or 'm' modifiers for megabytes and 'K' or 'k' for kilobytes. To specify the size in bytes just don't use modifiers. NUMBER Unsigned integer.
DIRECTIVES When some option is not used (commented out or not included in the configuration file at all) clamd takes a default action. Example If this option is set clamd will not run. LogFile STRING Save all reports to a log file. Default: disabled LogFileUnlock BOOL By default the log file is locked for writing and only a single daemon process can write to it. This option disables the lock. Default: no LogFileMaxSize SIZE Maximum size of the log file. Value of 0 disables the limit. Default: 1048576 LogTime BOOL Log time for each message. Default: no LogClean BOOL Log all clean files. Useful in debugging but drastically increases the log size. Default: no LogSyslog BOOL Use the system logger (can work together with LogFile). Default: no LogFacility STRING Type of syslog messages Please refer to 'man syslog' for facility names. Default: LOG_LOCAL6 LogVerbose BOOL Enable verbose logging. Default: no LogRotate BOOL Rotate log file. Requires LogFileMaxSize option set prior to this option. Default: no ExtendedDetectionInfo BOOL Log additional information about the infected file, such as its size and hash, together with the virus name. Default: no PidFile STRING Save the process identifier of a listening daemon (main thread) to a specified file. Default: disabled TemporaryDirectory STRING This option allows you to change the default temporary directory. Default: system specific (usually /tmp or /var/tmp). DatabaseDirectory STRING This option allows you to change the default database directory. If you enable it, please make sure it points to the same directory in both clamd and freshclam. Default: defined at configuration (/usr/local/share/clamav) OfficialDatabaseOnly BOOL Only load the official signatures published by the ClamAV project. Default: no LocalSocket STRING Path to a local (Unix) socket the daemon will listen on. Default: disabled LocalSocketGroup STRING Sets the group ownership on the unix socket. Default: the primary group of the user running clamd LocalSocketMode STRING Sets the permissions on the unix socket to the specified mode. Default: socket is world readable and writable FixStaleSocket BOOL Remove stale socket after unclean shutdown. Default: yes TCPSocket NUMBER TCP port number the daemon will listen on. Default: disabled TCPAddr STRING By default clamd binds to INADDR_ANY. This option allows you to restrict the TCP address and provide some degree of pro‐ tection from the outside world. This option can be specified multiple times in order to listen on multiple IPs. IPv6 is now supported. Default: disabled MaxConnectionQueueLength NUMBER Maximum length the queue of pending connections may grow to. Default: 200 StreamMaxLength SIZE Close the STREAM session when the data size limit is exceeded. The value should match your MTA's limit for the maximum attachment size. Default: 25M StreamMinPort NUMBER The STREAM command uses an FTP-like protocol. This option sets the lower boundary for the port range. Default: 1024 StreamMaxPort NUMBER This option sets the upper boundary for the port range. Default: 2048 MaxThreads NUMBER Maximum number of threads running at the same time. Default: 10 ReadTimeout NUMBER This option specifies the time (in seconds) after which clamd should timeout if a client doesn't provide any data. Default: 120 CommandReadTimeout NUMBER This option specifies the time (in seconds) after which clamd should timeout if a client doesn't provide any initial command after connecting. Note: the timeout for subsequents commands, and/or data chunks is specified by ReadTimeout. Default: 5 SendBufTimeout NUMBER This option specifies how long to wait (in milliseconds) if the send buffer is full. Keep this value low to prevent clamd hanging. Default: 500 MaxQueue NUMBER Maximum number of queued items (including those being processed by MaxThreads threads). It is recommended to have this value at least twice MaxThreads if possi‐ ble. WARNING: you shouldn't increase this too much to avoid running out of file descrip‐ tors, the following condition should hold: MaxThreads*MaxRecursion + MaxQueue - MaxThreads + 6 < RLIMIT_NOFILE. RLIMIT_NOFILE is the maximum number of open file descriptors (usually 1024), set by ulimit -n. Default: 100 IdleTimeout NUMBER This option specifies how long (in seconds) the process should wait for a new job. Default: 30 ExcludePath REGEX Don't scan files and directories matching REGEX. This directive can be used multi‐ ple times. Default: disabled MaxDirectoryRecursion NUMBER Maximum depth directories are scanned at. Default: 15 FollowDirectorySymlinks BOOL Follow directory symlinks. Default: no CrossFilesystems BOOL Scan files and directories on other filesystems. Default: yes FollowFileSymlinks BOOL Follow regular file symlinks. Default: no SelfCheck NUMBER This option specifies the time intervals (in seconds) in which clamd should perform a database check. Default: 600 VirusEvent COMMAND Execute a command when a virus is found. In the command string %v will be replaced with the virus name. Additionally, two environment variables will be defined: $CLAM_VIRUSEVENT_FILENAME and $CLAM_VIRUSEVENT_VIRUSNAME. Default: disabled ExitOnOOM BOOL Stop daemon when libclamav reports out of memory condition. Default: no AllowAllMatchScan BOOL Permit use of the ALLMATCHSCAN command. Default: yes Foreground BOOL Don't fork into background. Default: no Debug BOOL Enable debug messages from libclamav. Default: no LeaveTemporaryFiles BOOL Do not remove temporary files (for debugging purpose). Default: no User STRING Run the daemon as a specified user (the process must be started by root). Default: disabled Bytecode BOOL With this option enabled ClamAV will load bytecode from the database. It is highly recommended you keep this option turned on, otherwise you may miss detections for many new viruses. Default: yes BytecodeSecurity STRING Set bytecode security level. Possible values: TrustSigned - trust bytecode loaded from signed .c[lv]d files and insert run‐ time safety checks for bytecode loaded from other sources, Paranoid - don't trust any bytecode, insert runtime checks for all. Recommended: TrustSigned, because bytecode in .cvd files already has these checks. Default: TrustSigned BytecodeTimeout NUMBER Set bytecode timeout in milliseconds. Default: 5000 BytecodeUnsigned BOOL Allow loading bytecode from outside digitally signed .c[lv]d files. Default: no BytecodeMode STRING Set bytecode execution mode. Possible values: Auto - automatically choose JIT if possible, fallback to interpreter ForceJIT - always choose JIT, fail if not possible ForceInterpreter - always choose interpreter Test - run with both JIT and interpreter and compare results. Make all failures fatal. Default: Auto DetectPUA BOOL Detect Possibly Unwanted Applications. Default: No ExcludePUA CATEGORY Exclude a specific PUA category. This directive can be used multiple times. See https://www.clamav.net/documents/potentially-unwanted-applications-pua for the com‐ plete list of PUA categories. Default: disabled IncludePUA CATEGORY Only include a specific PUA category. This directive can be used multiple times. See https://www.clamav.net/documents/potentially-unwanted-applications-pua for the complete list of PUA categories. Default: disabled AlgorithmicDetection BOOL In some cases (eg. complex malware, exploits in graphic files, and others), ClamAV uses special algorithms to provide accurate detection. This option controls the algorithmic detection. Default: yes ScanPE BOOL PE stands for Portable Executable - it's an executable file format used in all 32 and 64-bit versions of Windows operating systems. This option allows ClamAV to per‐ form a deeper analysis of executable files and it's also required for decompression of popular executable packers such as UPX. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes ScanELF BOOL Executable and Linking Format is a standard format for UN*X executables. This option allows you to control the scanning of ELF files. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes DetectBrokenExecutables BOOL With this option clamd will try to detect broken executables (both PE and ELF) and mark them as Broken.Executable. Default: no ScanMail BOOL Enable scanning of mail files. If you turn off this option, the original files will still be scanned, but without parsing individual messages/attachments. Default: yes ScanPartialMessages BOOL Scan RFC1341 messages split over many emails. You will need to periodically clean up $TemporaryDirectory/clamav-partial directory. WARNING: This option may open your system to a DoS attack. Never use it on loaded servers. Default: no PhishingSignatures BOOL With this option enabled ClamAV will try to detect phishing attempts by using sig‐ natures. Default: yes PhishingScanURLs BOOL Scan URLs found in mails for phishing attempts using heuristics. This will classify "Possibly Unwanted" phishing emails as Phishing.Heuristics.Email.* Default: yes PhishingAlwaysBlockCloak BOOL Always block cloaked URLs, even if URL isn't in database. This can lead to false positives. Default: no PhishingAlwaysBlockSSLMismatch BOOL Always block SSL mismatches in URLs, even if the URL isn't in the database. This can lead to false positives. Default: no PartitionIntersection BOOL Detect partition intersections in raw disk images using heuristics. Default: no HeuristicScanPrecedence BOOL Allow heuristic match to take precedence. When enabled, if a heuristic scan (such as phishingScan) detects a possible virus/phishing it will stop scanning immedi‐ ately. Recommended, saves CPU scan-time. When disabled, virus/phishing detected by heuristic scans will be reported only at the end of a scan. If an archive contains both a heuristically detected virus/phishing, and a real malware, the real malware will be reported. Keep this disabled if you intend to handle "*.Heuristics.*" viruses differently from "real" malware. If a non-heuristically-detected virus (signature-based) is found first, the scan is interrupted immediately, regardless of this config option. Default: no StructuredDataDetection BOOL Enable the DLP module. Default: no StructuredMinCreditCardCount NUMBER This option sets the lowest number of Credit Card numbers found in a file to gener‐ ate a detect. Default: 3 StructuredMinSSNCount NUMBER This option sets the lowest number of Social Security Numbers found in a file to generate a detect. Default: 3 StructuredSSNFormatNormal BOOL With this option enabled the DLP module will search for valid SSNs formatted as xxx-yy-zzzz. Default: Yes StructuredSSNFormatStripped BOOL With this option enabled the DLP module will search for valid SSNs formatted as xxxyyzzzz. Default: No ScanHTML BOOL Perform HTML/JavaScript/ScriptEncoder normalisation and decryption. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes ScanOLE2 BOOL This option enables scanning of OLE2 files, such as Microsoft Office documents and .msi files. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes OLE2BlockMacros BOOL With this option enabled OLE2 files with VBA macros, which were not detected by signatures will be marked as "Heuristics.OLE2.ContainsMacros". Default: no BlockMax BOOL Flag files with "Heuristics.Limits.Exceeded" when scanning is incomplete due to exceeding a scan or file size limit. Default: no ScanPDF BOOL This option enables scanning within PDF files. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes ScanSWF BOOL This option enables scanning within SWF files. If you turn off this option, the original files will still be scanned, but without decoding and additional processing. Default: yes ScanXMLDOCS BOOL This option enables scanning xml-based document files supported by libclamav. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes ScanHWP3 BOOL This option enables scanning HWP3 files. If you turn off this option, the original files will still be scanned, but without additional processing. Default: yes ScanArchive BOOL Scan within archives and compressed files. If you turn off this option, the original files will still be scanned, but without unpacking and additional processing. Default: yes ArchiveBlockEncrypted BOOL Mark encrypted archives as viruses (Encrypted.Zip, Encrypted.RAR). Default: no ForceToDisk This option causes memory or nested map scans to dump the content to disk. If you turn on this option, more data is written to disk and is available when the leave-temps option is enabled at the cost of more disk writes. Default: no MaxScanSize SIZE Sets the maximum amount of data to be scanned for each input file. Archives and other containers are recursively extracted and scanned up to this value. The size of an archive plus the sum of the sizes of all files within archive count toward the scan size. For example, a 1M uncompressed archive containing a single 1M inner file counts as 2M toward the max scan size. Warning: disabling this limit or set‐ ting it too high may result in severe damage to the system. Default: 100M MaxFileSize SIZE Files larger than this limit won't be scanned. Affects the input file itself as well as files contained inside it (when the input file is an archive, a document or some other kind of container). Warning: disabling this limit or setting it too high may result in severe damage to the system. Default: 25M MaxRecursion NUMBER Nested archives are scanned recursively, e.g. if a Zip archive contains a RAR file, all files within it will also be scanned. This options specifies how deeply the process should be continued. Warning: setting this limit too high may result in severe damage to the system. Default: 16 MaxFiles NUMBER Number of files to be scanned within an archive, a document, or any other kind of container. Warning: disabling this limit or setting it too high may result in severe damage to the system. Default: 10000 MaxEmbeddedPE SIZE This option sets the maximum size of a file to check for embedded PE. Files larger than this value will skip the additional analysis step. Negative values are not allowed. Default: 10M MaxHTMLNormalize SIZE This option sets the maximum size of a HTML file to normalize. HTML files larger than this value will not be normalized or scanned. Negative values are not allowed. Default: 10M MaxHTMLNoTags SIZE This option sets the maximum size of a normalized HTML file to scan. HTML files larger than this value after normalization will not be scanned. Negative values are not allowed. Default: 2M MaxScriptNormalize SIZE This option sets the maximum size of a script file to normalize. Script content larger than this value will not be normalized or scanned. Negative values are not allowed. Default: 5M MaxZipTypeRcg SIZE This option sets the maximum size of a ZIP file to reanalyze type recognition. ZIP files larger than this value will skip the step to potentially reanalyze as PE. Negative values are not allowed. WARNING: setting this limit too high may result in severe damage or impact perfor‐ mance. Default: 1M MaxPartitions SIZE This option sets the maximum number of partitions of a raw disk image to be scanned. Raw disk images with more partitions than this value will have up to the value par‐ titions scanned. Negative values are not allowed. WARNING: setting this limit too high may result in severe damage or impact perfor‐ mance. Default: 50 MaxIconsPE SIZE This option sets the maximum number of icons within a PE to be scanned. PE files with more icons than this value will have up to the value number icons scanned. Negative values are not allowed. WARNING: setting this limit too high may result in severe damage or impact perfor‐ mance. Default: 100 MaxRecHWP3 NUMBER This option sets the maximum recursive calls to HWP3 parsing function. HWP3 files using more than this limit will be terminated and alert the user. Scans will be unable to scan any HWP3 attachments if the recursive limit is reached. Negative values are not allowed. WARNING: setting this limit too high may result in severe damage or impact perfor‐ mance. Default: 16 PCREMatchLimit NUMBER This option sets the maximum calls to the PCRE match function during an instance of regex matching. Instances using more than this limit will be terminated and alert the user but the scan will continue. For more information on match_limit, see the PCRE documentation. Negative values are not allowed. WARNING: setting this limit too high may severely impact performance. Default: 10000 PCRERecMatchLimit NUMBER This option sets the maximum recursive calls to the PCRE match function during an instance of regex matching. Instances using more than this limit will be terminated and alert the user but the scan will continue. For more information on match_limit_recursion, see the PCRE documentation. Negative values are not allowed and values > PCREMatchLimit are superfluous. WARNING: setting this limit too high may severely impact performance. Default: 5000 PCREMaxFileSize SIZE This option sets the maximum filesize for which PCRE subsigs will be executed. Files exceeding this limit will not have PCRE subsigs executed unless a subsig is encompassed to a smaller buffer. Negative values are not allowed. Setting this value to zero disables the limit. WARNING: setting this limit too high or disabling it may severely impact perfor‐ mance. Default: 25M ScanOnAccess BOOL This option enables on-access scanning (Linux only) Default: disabled OnAccessIncludePath STRING This option specifies a directory (including all files and directories inside it), which should be scanned on access. This option can be used multiple times. Default: disabled OnAccessExcludePath STRING This option allows excluding directories from on-access scanning. It can be used multiple times. Default: disabled OnAccessExcludeRootUID BOOL With this option you can whitelist the root UID (0). Processes run under root will be able to access all files without triggering scans or permission denied events. Note that if clamd cannot check the uid of the process that generated an on-access scan event (e.g., because OnAccessPrevention was not enabled, and the process already exited), clamd will perform a scan. Thus, setting OnAccessExcludeRootUID is not guaranteed to prevent every access by the root user from triggering a scan (unless OnAccessPrevention is enabled). Default: no OnAccessExcludeUID NUMBER With this option you can whitelist specific UIDs. Processes with these UIDs will be able to access all files without triggering scans or permission denied events. This option can be used multiple times (one per line). Note: using a value of 0 on any line will disable this option entirely. To whitelist the root UID (0) please enable the OnAccessExcludeRootUID option. Also note that if clamd cannot check the uid of the process that generated an on- access scan event (e.g., because OnAccessPrevention was not enabled, and the process already exited), clamd will perform a scan. Thus, setting OnAccessEx‐ cludeUID is not guaranteed to prevent every access by the specified uid from trig‐ gering a scan (unless OnAccessPrevention is enabled). Default: disabled OnAccessMaxFileSize SIZE Files larger than this value will not be scanned in on access. Default: 5M OnAccessMountPath STRING Specifies a mount point (including all files and directories under it), which should be scanned on access. This option can be used multiple times. Default: disabled OnAccessDisableDDD BOOL Disables the dynamic directory determination system which allows for recursively watching include paths. Default: no OnAccessPrevention BOOL Enables fanotify blocking when malicious files are found. Default: disabled DisableCertCheck BOOL Disable authenticode certificate chain verification in PE files. Default: no
NOTES All options expressing a size are limited to max 4GB. Values in excess will be reset to the maximum.
FILES /etc/clamav/clamd.conf
AUTHORS Tomasz Kojm <@clamav.net>, Kevin Lin <@sourcefire.com>
SEE ALSO clamd(8), clamdscan(1), clamav-milter(8), freshclam(1), freshclam.conf(5)
ClamAV 0.100.2 December 4, 2013 clamd.conf(5)
This manual Reference Other manuals
clamd.conf(5) referred by clamav-milter(8) | clamav-milter.conf(5) | clamconf(1) | clamd(8) | clamdscan(1) | clamdtop(1) | freshclam(1) | freshclam.conf(5)
refer to clamav-milter(8) | clamd(8) | clamdscan(1) | freshclam(1) | freshclam.conf(5)