Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 53cfccbb5e14c9ae…

MALICIOUS

RTF / .DOC

1.60 MB First seen: 2022-05-12
MD5: 42cd03b537635eabf21afc11f0db1de1 SHA-1: 8a70e38cacb8438f547b10e7e650e0ee5d97677a SHA-256: 53cfccbb5e14c9aec53709e87948d6bb0adae3f989d5eb446147989cc4b0327f
180 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that exploits CVE-2017-11882 via the Equation Editor. The embedded object likely contains and executes a malicious script. The RTF_EQUATION_EDITOR and CVE_2017_11882_ACTIVATION_RELATED heuristics confirm the exploit. The DOC BODY excerpt contains VBA-like code, suggesting the exploit's purpose is to run malicious code, likely for further payload delivery or system compromise.

Heuristics 5

  • 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.
  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000129e.bin
07231aa06d2d5efc77c87c4f4c59b864a1e6521226c843c910105dde3b882e2e		 rtf-objdata-decoded RTF \objdata at offset 0x129E 86195 bytes
objdata_01_off00036d66.bin
c6836530895d3068b0bd13b6673e20cfb3c2472da47cd4c3fb2419898144731b		 rtf-objdata-decoded RTF \objdata at offset 0x36D66 345132 bytes

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