Malicious RTF — malware analysis report

Static analysis result for SHA-256 4d0346037dc2d7ea…

MALICIOUS

RTF

841.5 KB Created: 2018-03-12 22:44:00 First seen: 2018-06-21
MD5: 0585253320d06abc4e9f805d185925bf SHA-1: 1b4f6a338a2b0a262a32c53140fc7e482cf9b859 SHA-256: 4d0346037dc2d7ea8bc814dcd78718a5b22d3fa33b275bb3dbd7c7285bb54152
262 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains multiple embedded OLE objects and triggers an ".objupdate" command, which is indicative of exploiting vulnerabilities like CVE-2017-8759 for client execution. ClamAV detections further confirm its malicious nature, flagging it as Doc.Macro.Obfuscation. The primary attack vector is likely spearphishing attachment, with the embedded OLE object serving as the mechanism to download and execute a secondary payload.

Heuristics 6

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • ClamAV: Xls.Downloader.Generic-6750544-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Generic-6750544-0
  • \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 10 \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 http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002c52.bin rtf-objdata-decoded RTF \objdata at offset 0x2C52 28731 bytes
SHA-256: 94bcdcb8de2c9f8e9975b1e86b12c991fc9bd48c0b2d9861ab43c9696b51565f
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_01_off00016c99.bin rtf-objdata-decoded RTF \objdata at offset 0x16C99 28731 bytes
SHA-256: 518f7239245053ff17d6bf8abf8ae0aa4b9b2b7a58fe64f86138a14d871418c8
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_03_off0003ed27.bin rtf-objdata-decoded RTF \objdata at offset 0x3ED27 28731 bytes
SHA-256: d8455cbf718690f70ea661006b7a6a7d2f70ccc4902dc7a887cfd82891173f3c
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_05_off00066e01.bin rtf-objdata-decoded RTF \objdata at offset 0x66E01 28731 bytes
SHA-256: bc3c42e1851315b86266e491c81303fa5f0c1137ac76d2454498b1a945ea4377
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_07_off0008ee8f.bin rtf-objdata-decoded RTF \objdata at offset 0x8EE8F 28731 bytes
SHA-256: ad37dcf019c8a09664e1c64315dbae11bcfaad3cd22b18f62f5dfd03de132dbc
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_08_off000a2ed6.bin rtf-objdata-decoded RTF \objdata at offset 0xA2ED6 28731 bytes
SHA-256: c09e76e367f438a08277f1427f8466c7e3df68561d2e6c9a539fa68e93eab946
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely
objdata_09_off000b6f1d.bin rtf-objdata-decoded RTF \objdata at offset 0xB6F1D 28731 bytes
SHA-256: bb0d1c5d6916ce963c0761d4976eeb16242c504d8b55a77515a995976d1dca2b
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely