RTF malware analysis — malicious · ebbbbeacf7fa2b9b

MALICIOUS

RTF

2.66 MB

MD5: a9a88e58b6fb6b3437dd6665106a9159 SHA-1: a66f7c122a962967a7cd49b518707a024e17873a SHA-256: ebbbbeacf7fa2b9be68aa4c8aa5d0b99d2d30d8a04b2866a42cac2b804d25909

222 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Phishing: Spearphishing Attachment T1027 Obfuscated Files or Information

The sample is a malicious RTF document containing an embedded OLE object with the Equation.3 ProgID and the objupdate control word to force automatic activation. Heuristics and static analysis identify a high-entropy payload (mz_offset=0x14CB) embedded within the OLE object, which is characteristic of the CVE-2017-11882/CVE-2018-0802 exploit delivery mechanism. No scripts were extracted from this sample, but the embedded binary artifact (objdata_00_00_off0000008c.bin) likely serves as the second-stage payload.

Heuristics 6

Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED

RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact 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.
Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX

RTF contains ~2792KB of hex-encoded data inside \objdata sections — may hide a payload
OLE object data medium RTF_OBJDATA

RTF contains 2 \objdata section(s) — embedded OLE objects
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off0000008c.bin` `5836f6f7a94e6fe98ef605aa828124753301e6ba79e821b2a13494e6dfcf4ca5`	rtf-objdata-decoded	RTF \objdata at offset 0x8C	1396137 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 8.00, consistent with packed or encrypted content.

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