Okrum leverages the HTTP protocol for C2 communication, while hiding the actual messages in the Cookie and Set-Cookie headers of the HTTP requests.2
tool
Okrum S0439
- Type
- malware
- Platform
- Windows
- Created
- 6 May 2020
- Last modified
- 25 April 2025
Okrum is a Windows backdoor that has been seen in use since December 2016 with strong links to Ke3chang.[1]
34
TechniquesTop 5%
9
TacticsTop 11%
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 S0439
Okrum leverages the HTTP protocol for C2 communication, while hiding the actual messages in the Cookie and Set-Cookie headers of the HTTP requests.3
Okrum was seen using MimikatzLite to perform credential dumping.4
Okrum was seen using modified Quarks PwDump to perform credential dumping.5
Okrum can collect network information, including the host IP address, DNS, and proxy information.6
Okrum's payload is encrypted and embedded within its loader, or within a legitimate PNG file.7
Standing S0439
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
Techniques34Top 5%
95th percentile · 95% of 825 ATT&CK software entries have this many Enterprise techniques or fewer.
Tactics9Top 11%
89th percentile · 89% 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 / technique15.5med35th pct
35th percentile · 65% of 825 ATT&CK software entries have more detection rules per technique.
Tests / technique6med
Detection coverage S0439
865 distinct rules cover the 34 techniques recorded for this tool. The 926 technique-to-rule mappings resolve to 865 distinct rules, because one rule can cover several techniques. 627 Sigma · 238 Splunk.
31 covered by at least one rule3 with no coverage865 distinct rules in total
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