Malicious RTF — malware analysis report

Static analysis result for SHA-256 617109092b80559f…

MALICIOUS

RTF

841.5 KB Created: 2018-03-12 22:46:00 First seen: 2018-06-21
MD5: 595647a0c62c25da84594411de42bbac SHA-1: 78936304a7ee6033daf5c0ef702b70aaf6108d14 SHA-256: 617109092b80559ffede94ad632e7de23b7fbe804089fd812f5e60084174e408
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 6

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: 316f6776613e45d995174e1872cc98957d092372f7b6ea12acc1f9509fe8a0ce
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: d346db23039da4c28e767cc38cb3eefd5016a31616ed256935890835e9a640fc
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: 88aba2db941ce98addb983937f25ecc6286ac67499e68804bb758f27a501c6c4
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: 69645655b3bce10161ba9bbfe6c5e40b00b7716563907832fa4c8a82bd84a3ad
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: 0d3c9a157b4b5cf1d205a4e13b3f1d9e94eed652e829c8aa2cb8fe5441207492
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: a5c828851c847fecbc50bd32716795f898fc7e63869a89c537fdeec85d95b4c0
Detection
ClamAV: Xls.Downloader.Generic-6750544-0
Obfuscation or payload: unlikely