Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 80af031c3c63c32d…

MALICIOUS

RTF / .DOC

14.7 KB
MD5: 259d0e20d993b313c224f0346cca9ad8 SHA-1: 2bac249e9118a274f53e4fbceee2904415d11014 SHA-256: 80af031c3c63c32d14aea820f4c9119d20d2c0ebe6b1f8b430b5a5b04dda3766
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document that contains embedded OLE objects and triggers an Equation Editor exploit. The ".objupdate" directive forces the OLE object to activate, leading to the exploitation of a known vulnerability. This technique is commonly used to download and execute 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_off00001448.bin
3da20bd6e2f8cb56101b05d114235d4d2d5e17288199e55d2aa25e19487c0560
rtf-objdata-decoded RTF \objdata at offset 0x1448 1410 bytes