Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d74a387b2f2f994b…

MALICIOUS

RTF / .DOC

16.4 KB
MD5: 7fa17096063670a1ca31a4e3bb842022 SHA-1: 7cdd753936a9a937c770ef9a3e025cfbd4311039 SHA-256: d74a387b2f2f994bd41c3ab8d64362c9a4d5bd101c1f4888a690d895bd6eeac1
120 Risk Score

Malware Insights

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

The sample is an RTF document containing OLE object data, specifically targeting the Equation Editor vulnerability. The \objupdate heuristic indicates that the embedded OLE object is automatically activated upon opening the document, which is a common technique for exploiting vulnerabilities like CVE-2017-11882. This exploit likely leads to the download and execution of a second-stage payload.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001b53.bin
7c467fc4b888ae1c8c08f3daa0e5b22adc7437eb1007806ef952023ecae49e9a
rtf-objdata-decoded RTF \objdata at offset 0x1B53 1299 bytes