Malicious PDF — malware analysis report

Static analysis result for SHA-256 db040013387d35cc…

MALICIOUS

PDF

72.8 KB Created: 2021-09-08 21:23:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9e1a839e2656bd93e11bf827da95b3e2 SHA-1: 5cda92350bf49a178d544ab82042666bff8ed490 SHA-256: db040013387d35cc5a920bed47c603f27f0f0a9e2ff6b58b186f849606b379a8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external links, many of which point to disposable hosting or compromised CMS upload directories. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a link farm intended to distribute malicious content or phish users. The embedded JavaScript, while not fully analyzed due to obfuscation, likely contributes to the malicious functionality by executing further stages or redirecting the user. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://prevodi-plovdiv.com/userfiles/file/48235205718.pdf In PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613644efc0e5c---8979927512.pdfIn PDF document text
    • https://cnn-logistics.com/asset/files/lewej.pdfIn PDF document text
    • http://cathyourhair.nl/js/ckfinder/userfiles/files/vaxutuwuseripumimumuvonup.pdfIn PDF document text
    • http://kelt.pl/userfiles/file/dumil.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/62682618978.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/2450792973.pdfIn PDF document text
    • https://swift-tw.com/lcc/upload/files/58029345769.pdfIn PDF document text
    • http://merydian.pl/nowymerydian/userfiles/file/39812031158.pdfIn PDF document text
    • http://tuzy.pl/Upload/file/77138118299.pdfIn PDF document text
    • http://kelkenaghshband.com/app/webroot/img/files/vefatalijag.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/erb45m3r9993j71m85soimbolm/juxilezezozeza.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/30889013242.pdfIn PDF document text
    • https://apc-algercentre.dz/ckfinder/userfiles/files/jamijalofodigonekoxo.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/ut7o70fe8ccokgkgvc70fm3ri0/84343045329.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/fanotagokinoxijo.pdfIn PDF document text
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/25075151846.pdfIn PDF document text
    • http://jagdrevier.hu/upload/images/file/4812812677.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/nunufototiwudatexojedupa.pdfIn PDF document text
    • http://factory-01.com/js/upload/files/90381459006.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=af+form+1975+pdfPDF 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_off0000b9c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9C7 17604 bytes
SHA-256: 31e488f0a797dc15c801738f9c4d97a56673d527a3b2117e3cf2cc17b7f4152d
font_01_sfnt_off0000e728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE728 10240 bytes
SHA-256: 7571709f0e4ba6a06a800c3e2efc2d867d851b0c39800ae7f2a5c3999d8cc59d
font_02_sfnt_off0000fe44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1