FoggyWeb can retrieve configuration data from a compromised AD FS server.2
tool
FoggyWeb S0661
- Type
- malware
- Platform
- Windows
- Created
- 16 November 2021
- Last modified
- 11 April 2024
FoggyWeb is a passive and highly-targeted backdoor capable of remotely exfiltrating sensitive information from a compromised Active Directory Federated Services (AD FS) server. It has been used by APT29 since at least early April 2021.[1]
21
TechniquesTop 18%
8
TacticsTop 20%
1
Threat groupunranked
0
CampaignsNone recorded
Enterprise ATT&CK only. Any Mobile or ICS rows on the same ATT&CK page are not carried.
MITRE reference S0661
FoggyWeb can compile and execute source code sent to the compromised AD FS server via a specific HTTP POST.3
FoggyWeb can masquerade the output of C2 commands as a fake, but legitimately formatted WebP file.5
FoggyWeb can be disguised as a Visual Studio file such as Windows.Data.TimeZones.zh-PH.pri to evade detection. Also, FoggyWeb's loader can mimic a genuine dll file that carries out the same import functions as the legitimate Windows version.dll file.6
FoggyWeb can configure custom listeners to passively monitor all incoming HTTP GET and POST requests sent to the AD FS server from the intranet/internet and intercept HTTP requests that match the custom URI patterns defined by the actor.7
Standing S0661
Reach is how much of ATT&CK this tool touches. Coverage is how well defended each thing it does is, as a median per technique rather than a total — a total would just restate the reach. Each figure is ranked against all 825 ATT&CK software entries only where that population actually spreads. Where most of the population shares one value, a percentile would rank the tie instead of the entity, so the raw value is shown and no rank is claimed.
Reach
Techniques21Top 18%
82nd percentile · 82% of 825 ATT&CK software entries have this many Enterprise techniques or fewer.
Tactics8Top 20%
80th percentile · 80% of 825 ATT&CK software entries have this many tactics spanned or fewer.
Threat group161% tie · 22 values
61% of the population shares a single value across only 22 distinct values, so a percentile here would rank the tie, not the entity.
Campaigns085% tie · 8 values
85% of the population shares a single value across only 8 distinct values, so a percentile here would rank the tie, not the entity.
Coverage
Rules / technique13medBottom 25%
25th percentile · 75% of 825 ATT&CK software entries have more detection rules per technique.
Tests / technique3med
Detection coverage S0661
529 distinct rules cover the 21 techniques recorded for this tool. The 544 technique-to-rule mappings resolve to 529 distinct rules, because one rule can cover several techniques. 393 Sigma · 136 Splunk.
18 covered by at least one rule3 with no coverage529 distinct rules in total
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