Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5841fd3dfc43d5be…

MALICIOUS

RTF / .DOC

3.3 KB
MD5: f5d758978832ef839efad3df01093b20 SHA-1: b89798c9bc007ab6be77537ae313f17420565ea6 SHA-256: 5841fd3dfc43d5bebd85dc5fd7b57c2663ee75ee04816ba008d4c39a375ef69a
180 Risk Score

Malware Insights

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

The RTF file contains embedded OLE objects and specifically triggers the CVE-2017-11882 vulnerability related to the Equation Editor. This indicates the file is designed to exploit this known vulnerability for code execution upon opening. No further stages or IOCs were identified in 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_off000000b4.bin
ddfe8940c4778ea7a76e0b2754e2f493efa6ce6199e7a41d4c1f34efc9634c2c
rtf-objdata-decoded RTF \objdata at offset 0xB4 1437 bytes