Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 306caca869e40f7d…

MALICIOUS

RTF / .DOC

32.0 KB First seen: 2022-12-06
MD5: 4fb9a0f253fae2dcd2ebd9327855706e SHA-1: 61f9c00a4f2cb2c5acefc497bbe9c035ef4b5b8b SHA-256: 306caca869e40f7d5a867f3ab7e91493886210888715b26f55578517a75889ad
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object that exploits a known vulnerability in the Equation Editor component. The presence of \objupdate indicates an attempt to automatically activate the embedded object, which is a common technique for exploiting this vulnerability. The document also contains a lure instructing the user to 'Enable editing', further suggesting malicious intent.

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_off00005acd.bin
3328c0274e5ae87a5f9a747657d0eebdac510dac58f9cb59e4359decc86e7504
rtf-objdata-decoded RTF \objdata at offset 0x5ACD 1702 bytes