Malicious PDF — malware analysis report

Static analysis result for SHA-256 431c11548dc383b1…

MALICIOUS

PDF

99.3 KB Created: 2021-09-02 21:12:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4dae8aa8140bb38325a98b1f95f2ab23 SHA-1: 51ff519222862f22aff4d8ceb13c6dd5f7aebc12 SHA-256: 431c11548dc383b19aba468aac5b09a78d41c17e275cd6f4d8255919facc23f1
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. No scripts were extracted, but the structure and URL patterns strongly indicate a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://philabc.ru/uplcv?utm_term=ncic+operating+manual+introduction PDF link annotation
    • https://coolingrealestate.com/your-home-cleaner/FCKuploads/file/67269849893.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/faberoradiv.pdfIn PDF document text
    • http://hopsch.de/uploads/file/dofawewodigemibudupe.pdfIn PDF document text
    • https://kurek-rowery.pl/user_pict/file/69229155193.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608503486e052---42655971061.pdfIn PDF document text
    • http://volamtuyetthe.com/userfiles/file/fufoxodanopefivaf.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202104300723206496.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/kv5ckcig7pgouphto159t3edh6/49206922128.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/10594777739.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/26446707994.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ccff5b103---2921662555.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/22658321186.pdfIn PDF document text
    • https://dogathermalhotel.com/resimler/files/wabavepovibi.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aab3881ffa4---79679772301.pdfIn PDF document text
    • http://petukmahaaaraj.com/userfiles/file/taregubakisuwalewo.pdfIn PDF document text
    • https://associazionebriciole.it/public/file/98498592026.pdfIn PDF document text
    • http://angeladaniel.de/uploads/files/30947342517.pdfIn PDF document text
    • http://tasarimak.net/ckfinder/userfiles/files/17455826419.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608312fe136ba---18148132700.pdfIn PDF document text
    • http://atmaircenter.com/lb/userfiles/files/56637267477.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/51384892042.pdfIn PDF document text
    • http://dynamicyunnan.com/ckfinder/userfiles/files/bijeroxuxizetamedo.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/gewepoladenejamageg.pdfIn PDF document text
    • 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_off000121a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000139b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139B8 17388 bytes
SHA-256: 88984ce2e589628612472f2bd10a3a3ac0760bb463ed77700234db7ca2f31440
font_02_sfnt_off0001672e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1672E 10764 bytes
SHA-256: 77d9d1f1e2312807e0d533218fe4703feade66020bcb71f3ffa0c72827dc0853

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