Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c6c2c394b87ce18a…

MALICIOUS

RTF / .DOC

29.3 KB First seen: 2022-11-15
MD5: 274886076d8afd387cdb8a13be42af56 SHA-1: 61957b6b27f32a9dc42ff36000dace0d467e7f11 SHA-256: c6c2c394b87ce18acc7ae314d4253525639ecf5d27e6f133a17ba31e92b0a98f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object with an Equation Editor ProgID, which is a known exploit vector. The ".objupdate" directive forces OLE activation, and the document body includes a lure instructing the user to 'Enable editing'. This combination strongly suggests an attempt to exploit a vulnerability, likely CVE-2017-11882, to execute a payload.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000581c.bin
6d20ed60da189a1a82ed7ef86fba57917015478c0c1f86643d9b93056b480744
rtf-objdata-decoded RTF \objdata at offset 0x581C 1670 bytes