Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c584c93d6988392d…

MALICIOUS

RTF / .DOC

24.8 KB First seen: 2021-09-17
MD5: 6e076a4ce0c18b9b693865b2b6d619de SHA-1: b08be1cf4fd686468c3c36f81020071c6babe86b SHA-256: c584c93d6988392de66928284d712adc916a93063773f82b44c44ce189650668
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data and triggers an objupdate event, indicating it's designed to activate embedded objects. The critical firing for RTF_EQUATION_EDITOR strongly suggests exploitation of a known vulnerability in the Equation Editor component. This technique is commonly used to achieve remote code execution, typically to download and execute a second-stage malware 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_off00001f03.bin
1eb1b76f3285755f2bb20f27fec1b8c1faf83b6514b473b85aedd8ff900ef920
rtf-objdata-decoded RTF \objdata at offset 0x1F03 2106 bytes