Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d87f02cd867a7cc…

MALICIOUS

PDF

85.5 KB Created: 2021-10-18 06:47:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 7b7281e4305a3e3517a0f0052ebbd800 SHA-1: 741ef887d9fab31e30971e9277a821a31f2d07ab SHA-256: 9d87f02cd867a7ccf5597b742018f7d525859254642d9471f663c627437e7448
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous external URLs are embedded within the document, and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates these are likely part of a scheme to direct users to potentially harmful sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://eternalcycle.com/FCKFiles/file/givisifonowaxoxanuwatawe.pdf In PDF document text
    • http://ty-int.com/files/files/vorejebimabenimobosof.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/tinimonowi.pdfIn PDF document text
    • https://www.edmcenter.xyz/ckfinder/userfiles/files/60894073418.pdfIn PDF document text
    • http://cdn.eagle.mn/uploads/userfiles/files/18513912308.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16166ed114652d---sufalokubu.pdfIn PDF document text
    • http://gzhangqin.com/uploadfile/files/ruriliduvumag.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/98293171920.pdfIn PDF document text
    • https://betentour.com/sites/default/files/file/kefajopifofu.pdfIn PDF document text
    • http://tagsu.com/attachments/fckattachments/file/92089824520.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202110061651439111.pdfIn PDF document text
    • http://pneusmarene.it/images/file/66068724007.pdfIn PDF document text
    • http://kaies.cn/upfiles/21092810321420275216tp3g.pdfIn PDF document text
    • http://grotech.in/userfiles/file/27460677626.pdfIn PDF document text
    • https://cyklo-wellness-penzion-palice.cz/content/gopabuwem.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/mefubokib.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/16718350569.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/fizudifobizonegikigowuxe.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vogenibosejetelewi.pdfIn PDF document text
    • http://hkacca.com/userfiles/goxevipilukeboxusuw.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/36720588002.pdfIn PDF document text
    • https://venefoil.com/ckfinder/userfiles/files/jaginapuwimolufev.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/suvilizubagawabafuliwode.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/cmwvf4RlXg4/uplcv?utm_term=structure+of+alpha+helix+proteinPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE890 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000100a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A2 18132 bytes
SHA-256: d2caebf40687c6bcd09c1ccbf48764bfe880016400d0966e7ca606e5a92a45f0
font_02_sfnt_off00013013.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13013 10684 bytes
SHA-256: 9f6e2884fce5b26c92c9aa8e8865fea87772b995ca30e68dc57ebb4b50084d7a