Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f4c7d87d210f4d0…

MALICIOUS

PDF

73.2 KB Created: 2021-10-10 11:57:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: b98718590c5dc20371e830b7e0aaa57d SHA-1: 0f136fbd24e4afacbdbfb4e24bf98cd6c7bb2d59 SHA-256: 5f4c7d87d210f4d0342283afb4b2ccbf33cbdccfd4b547ddef8ce51505e59ac8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crysiq.ru/uplcv?utm_term=meaning+of+maybe PDF link annotation
    • http://www.multigacos.com/admin/uploaded/fck/file/janevobopatijefusuwin.pdfIn PDF document text
    • http://podiummoda.ru/userfiles/file/21984180343.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/wilebijalufivoburokolidod.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/64f0893e6ad954054d8b0f7791003ffe/11523574307.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/24184230866.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/17738954406.pdfIn PDF document text
    • https://patoman.ro/ckfinder/userfiles/files/motopatunizema.pdfIn PDF document text
    • http://vnndt.com/Images_upload/files/52838966676.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/12942542890.pdfIn PDF document text
    • https://xn--49st2et51duvk.com/upload/files/22599986844.pdfIn PDF document text
    • http://jumpstart.mobi/ckfinder/userfiles/files/xumumexebiwo.pdfIn PDF document text
    • http://nkmate.com/FileData/ckfinder/files/20210925_D7E0F1089D8852B2.pdfIn PDF document text
    • https://limsurempat.com/contents/files/61050088066.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/vixejukow.pdfIn PDF document text
    • http://www.gobarging.com/uploads/textareas/file/fufedaxefakegux.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/cb414ffe4964a2a21d613ac152376c63/19053820420.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/us6bov1l1lu3vhj4qro8irrt3c/tukigezexuxulusexem.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/goxezoxade.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/kosozakazux.pdfIn PDF document text
    • https://texasbordervolunteers.org/userfiles/file/89412021539.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/jozinagosurutawezebeku.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/71663483947.pdfIn PDF document text
    • https://firmabudowlanawalczak.pl/web/uploads/files/11854726619.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/lasewega.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/90920967345.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_off0000bcc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D7 10392 bytes
SHA-256: 3093a7a0dcc42d3d045aacd5a5f6cfdf9a4e1bc51e50ca2efd93f0f03c80ffe9
font_02_sfnt_off0000ec59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC59 16596 bytes
SHA-256: 75f69bb6795b57b1cbc47b5bc69536b8a56a5a45a59a43e49cc96a6b3061c12a