WellMess can use junk data in the Base64 string for additional obfuscation.4
tool
WellMess S0514
- Type
- malware
- Platform
- Windows
- Created
- 24 September 2020
- Last modified
- 25 April 2025
WellMess is lightweight malware family with variants written in .NET and Golang that has been in use since at least 2018 by APT29.[1][2][3]
15
Techniques66th pct
5
Tactics41st pct
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 S0514
Standing S0514
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
Techniques1566th pct
66th percentile · 66% of 825 ATT&CK software entries have this many Enterprise techniques or fewer.
Tactics541st pct
41st percentile · 59% of 825 ATT&CK software entries have more tactics spanned.
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 / technique32medTop 20%
80th percentile · 80% of 825 ATT&CK software entries have this many detection rules per technique or fewer.
Tests / technique6med
Detection coverage S0514
723 distinct rules cover the 15 techniques recorded for this tool. The 790 technique-to-rule mappings resolve to 723 distinct rules, because one rule can cover several techniques. 519 Sigma · 204 Splunk.
13 covered by at least one rule2 with no coverage723 distinct rules in total
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