RTF malware analysis — malicious · 7979f0d43fb20a08

MALICIOUS

RTF

17.3 KB First seen: 2018-10-07

MD5: d78fbff3b463dffc7f7e1c0b5a5d4d27 SHA-1: 3d043a9e88bfc124dfa3080b608fe927b72ad6d4 SHA-256: 7979f0d43fb20a08775082bb3a7f2740bbda9e4fa904335af76e4057130f7978

200 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is an RTF document containing an embedded OLE object that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability is known to be used for arbitrary code execution, likely to download and run a secondary payload. The presence of ` tf10s24{\fonttbl{\f0\fswiss Helvetica;}} \pard\sa200\sl275\slmult1\f0\fs24\lang9 This is a test document.\par \pard\sa200\sl275\slmult1\objupdate\a \f0\fs24\lang9\object \objclass "Equation 3.0" \objdata ...` indicates the exploitation of this vulnerability. The `Ole10Native` stream and `objupdate` directive further confirm the malicious intent.

Heuristics 5

Equation Editor Ole10Native payload — CVE-2017-11882 likely critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE

RTF decodes to an activated Microsoft Equation 3.0 OLE storage whose payload is a high-entropy Ole10Native stream rather than normal Equation Native/MTEF data. This is a weaponized Equation Editor RCE delivery shape consistent with CVE-2017-11882/CVE-2018-0802.
Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM

RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
Automatically linked OLE object high RTF_OBJAUTLINK

RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
\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

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00000ef6.bin`	rtf-objdata-decoded	RTF \objdata at offset 0xEF6	4666 bytes
SHA-256: `846f970d71ecc952726da843668a90ec9afa87669a1ebdc6feb0a8e6a00d4a30`

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