File Download Via Bitsadmin To A Suspicious Target Folder

Severity: high
Author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects usage of bitsadmin downloading a file to a suspicious target folder

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1197` BITS Jobs
Defense Evasion	`T1036.003` Masquerading: Rename Legitimate Utilities, `T1197` BITS Jobs
Command & Control	`T1105` Ingress Tool Transfer

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\bitsadmin.exe'
OriginalFileName: bitsadmin.exe

Stage 2: `all of selection_flags`

or:
CommandLine|contains: ' /addfile '
CommandLine|contains: ' /create '
CommandLine|contains: ' /transfer '

Stage 3: `all of selection_folder`

or:
CommandLine|contains: '%ProgramData%'
CommandLine|contains: '%public%'
CommandLine|contains: '%temp%'
CommandLine|contains: '%tmp%'
CommandLine|contains: ':\Perflogs'
CommandLine|contains: ':\ProgramData\'
CommandLine|contains: ':\Temp\'
CommandLine|contains: ':\Users\Public\'
CommandLine|contains: ':\Windows\'
CommandLine|contains: '\$Recycle.Bin\'
CommandLine|contains: '\AppData\Local\'
CommandLine|contains: '\AppData\Roaming\'
CommandLine|contains: '\Contacts\'
CommandLine|contains: '\Desktop\'
CommandLine|contains: '\Favorites\'
CommandLine|contains: '\Favourites\'
CommandLine|contains: '\Music\'
CommandLine|contains: '\Pictures\'
CommandLine|contains: '\Start Menu\Programs\Startup\'
CommandLine|contains: '\Users\Default\'
CommandLine|contains: '\Videos\'
CommandLine|contains: '\inetpub\wwwroot\'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CommandLine`	match	`/addfile` corpus 5 (sigma 5) `/create` corpus 14 (sigma 14) `/transfer` corpus 5 (sigma 5) `%ProgramData%` corpus 4 (sigma 4) `%public%` `%temp%` corpus 5 (sigma 5) `%tmp%` corpus 9 (sigma 9) `:\Perflogs` corpus 3 (sigma 3) `:\ProgramData\` corpus 5 (sigma 5) `:\Temp\` corpus 14 (sigma 14) `:\Users\Public\` corpus 14 (sigma 14) `:\Windows\` corpus 2 (sigma 2) `\$Recycle.Bin\` `\AppData\Local\` corpus 8 (sigma 8) `\AppData\Roaming\` corpus 10 (sigma 10) `\Contacts\` corpus 6 (sigma 6) `\Desktop\` corpus 11 (sigma 11) `\Favorites\` corpus 6 (sigma 6) `\Favourites\` corpus 6 (sigma 6) `\Music\` corpus 2 (sigma 2) `\Pictures\` corpus 3 (sigma 3) `\Start Menu\Programs\Startup\` `\Users\Default\` `\Videos\` corpus 2 (sigma 2) `\inetpub\wwwroot\`
`Image`	ends_with	`\bitsadmin.exe` corpus 23 (sigma 23)
`OriginalFileName`	eq	`bitsadmin.exe` corpus 9 (sigma 9)