Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 580079199be61862…

MALICIOUS

RTF / .DOC

13.5 KB First seen: 2022-07-07
MD5: 45ce24480313f592e7c38acfc0c5a072 SHA-1: 7b696cd14d77775191469573e08c1881a2d50e80 SHA-256: 580079199be618624f63e831da2537f993f9dbc237123571096ecf4a60fd9b4d
200 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File T1059.005 PowerShell

The sample is an RTF document containing an embedded OLE object that exploits CVE-2017-11882 via the Equation Editor. The heuristic firings indicate obfuscated Equation Editor ProgID and activation, along with an \objupdate forcing OLE activation. The document body contains a lure instructing the user to 'enable editing', a common tactic for macro-based malware droppers.

Heuristics 6

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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
  • 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_off00001fee.bin
7f88e7ef57e4b76bd8531d6c9666084e9a729da2ce8db448b17b04b51a4f088d		 rtf-objdata-decoded RTF \objdata at offset 0x1FEE 1732 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.