RTF malware analysis — malicious · 0871a57057c27a8c

MALICIOUS

RTF

1.13 MB First seen: 2020-07-24

MD5: dc31413e6cfe107f2b25aa7c3c97c154 SHA-1: 6511108ba81dfb0aa711ac4f1b9afd65d99a4713 SHA-256: 0871a57057c27a8cc63902af5006bd6fe2aeba50babb87f48a85e67d5695cfdc

222 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains an embedded OLE object related to Microsoft Equation Editor, specifically triggering heuristics associated with CVE-2017-11882. This indicates the file is designed to exploit this vulnerability for client-side execution. The presence of a large, high-entropy OLE object suggests it likely contains and decodes a second-stage payload.

Heuristics 6

Split hex Equation Editor ProgID + OLE object critical CVE likely 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.
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.
\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 ~1180KB of hex-encoded data inside \objdata sections — may hide a payload
OLE object data medium RTF_OBJDATA

RTF contains 1 \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_off00000092.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x92	590217 bytes
SHA-256: `0d2a096f8ffb4873855b1e23d2a00618a685939cbc844e18a5a6a6375e2e5850`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.99, consistent with packed or encrypted content.

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