Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 afc4256312f7c930…

MALICIOUS

RTF / .DOC

4.2 KB
MD5: ac2fb4155b5e5823a0e140722976aecb SHA-1: c6315b8c81e63cddf6ff2396b10c545cfec4a750 SHA-256: afc4256312f7c930056fc0ca31d1893568f142cf9c810e0e765749bd43fea6dc
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains embedded OLE objects and specifically triggers the CVE-2017-11882 vulnerability related to Equation Editor. This indicates an attempt to exploit a client-side vulnerability for code execution. No specific malware family could be identified from the static analysis.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000075.bin
043ddcb56208eca8e3f91e0dabb5a929d0a1bf69dc61b1f9dbb0ed80a89d5290
rtf-objdata-decoded RTF \objdata at offset 0x75 1929 bytes