Detection rules › Splunk

IcedID Exfiltrated Archived File Creation

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects the creation of suspicious files named passff.tar and cookie.tar, which are indicative of archived stolen browser information such as history and cookies on a machine compromised with IcedID. It leverages Sysmon EventCode 11 to identify these specific filenames. This activity is significant because it suggests that sensitive browser data has been exfiltrated, which could lead to further exploitation or data breaches. If confirmed malicious, this could allow attackers to access personal information, conduct further phishing attacks, or escalate their presence within the network.

MITRE ATT&CK coverage

TacticTechniques
CollectionT1560.001 Archive Collected Data: Archive via Utility

Event coverage

ProviderEvent IDTitle
Sysmon11FileCreate

Stages and Predicates

Stage 1: tstats

tstats WHERE (Filesystem.file_path="*\\cookie.tar" OR Filesystem.file_path="*\\passff.tar") BY Filesystem.action, Filesystem.dest, Filesystem.file_access_time, Filesystem.file_create_time, Filesystem.file_hash, Filesystem.file_modify_time, Filesystem.file_name, Filesystem.file_path, Filesystem.file_acl, Filesystem.file_size, Filesystem.process_guid, Filesystem.process_id, Filesystem.user, Filesystem.vendor_product

Stage 2: search

search

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

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.

FieldKindValues
Filesystem.file_patheq
  • "*\\cookie.tar"
  • "*\\passff.tar"