Malicious RTF — malware analysis report

Static analysis result for SHA-256 bf8e1bac13c2015c…

MALICIOUS

RTF

876.9 KB Created: 2018-05-02 20:23:00 First seen: 2019-08-04
MD5: 082173d1c8a4d7766ea7956f54dc6ba6 SHA-1: bd48bd4e1eaa3eb050b026b48efcfba92f604055 SHA-256: bf8e1bac13c2015c89e7590908b4f818a3297d6f2acda7c4c989395688154576
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: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • \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 12 \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 12

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002c17.bin rtf-objdata-decoded RTF \objdata at offset 0x2C17 24123 bytes
SHA-256: 0d99b2ac8f6e83f1b1596a504be5755f17ab7df915b9b787d916297a27940bfa
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_01_off000142ce.bin rtf-objdata-decoded RTF \objdata at offset 0x142CE 24123 bytes
SHA-256: acc853ae5323e2fe36a8e5e558930c3a3ef20dada6589f49312b5645be4447c6
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_02_off00025985.bin rtf-objdata-decoded RTF \objdata at offset 0x25985 24123 bytes
SHA-256: 92acc8e44adb2b07a39537b5a119b8048c7373f0932b5eb7f87ba3a6ea10d77b
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_03_off0003703c.bin rtf-objdata-decoded RTF \objdata at offset 0x3703C 24123 bytes
SHA-256: 5264abb7e704b8f9e19dd22578bafe4df78533182a6b442472b0dc2ce05a9bf6
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_04_off000486f3.bin rtf-objdata-decoded RTF \objdata at offset 0x486F3 24123 bytes
SHA-256: 6279c524d98354cd983f9207f52bd19a72bce66d65cacd5474c66e2de5fb7d27
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_05_off00059daa.bin rtf-objdata-decoded RTF \objdata at offset 0x59DAA 24123 bytes
SHA-256: a04c92627a9b871c895dea4bdbdd76a4041822dee9c02188f218894d66e3231c
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_06_off0006b4ab.bin rtf-objdata-decoded RTF \objdata at offset 0x6B4AB 24123 bytes
SHA-256: 95440e83c27ab4f330df44df66da42263ef959ed23c1625de1c176bd913b6587
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_07_off0007cb62.bin rtf-objdata-decoded RTF \objdata at offset 0x7CB62 24123 bytes
SHA-256: ce4b010dad95d252d6c6fbf7b11a65845928c86ec9239a58a7b9b6027309059a
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_08_off0008e219.bin rtf-objdata-decoded RTF \objdata at offset 0x8E219 24123 bytes
SHA-256: 0c2b3a961b0e9e3655851b48a67bff1889a295172e7f145c6bfed88a499466b7
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_09_off0009f8d0.bin rtf-objdata-decoded RTF \objdata at offset 0x9F8D0 24123 bytes
SHA-256: 79ed5d5d95235766f67aa1ee9bc2d8e9721274b96dceff81bfb89063a495bb93
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_10_off000b0f87.bin rtf-objdata-decoded RTF \objdata at offset 0xB0F87 24123 bytes
SHA-256: 01ba4b3c62488f885f8bf2f7a0443c2a3fed2056637d322af5f12e67fa690221
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_11_off000c263e.bin rtf-objdata-decoded RTF \objdata at offset 0xC263E 24123 bytes
SHA-256: 9f666a68132453fbb1505fe180aaa83dcea041d13604a0841c6674cfe840ddb3
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely