Malicious PDF — malware analysis report

Static analysis result for SHA-256 10b10a9aac9f703d…

MALICIOUS

PDF

82.3 KB Created: 2021-09-20 12:24:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dbf20d01adeb05fb6d4ae8554aa520b0 SHA-1: 1a1d7c60eca0f25868bb944a9dea7704c5595344 SHA-256: 10b10a9aac9f703d8abd0fef7e61c22b6198f9be86648652e6acd1c8504b989f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to numerous unknown URLs, many hosted on potentially compromised or disposable domains, indicating a phishing or malware distribution attempt. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggests the document's purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://studiotecnicomaglio.it/userfiles/files/53224506412.pdf In PDF document text
    • https://learn-atdi.com/uploads/files/topuxoguf.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/33329452508.pdfIn PDF document text
    • https://mollis.rs/files/wopulugoridivifojukubi.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/vinitatozuzitutororotonu.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/dajure.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/96243823253.pdfIn PDF document text
    • http://topliving.sk/userfiles/file/79846370412.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210920164617_nsjvk9.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/43576299064.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16143c8f6566e0---zekuvanefopaga.pdfIn PDF document text
    • http://travelport.pl/userfiles/file/86455865133.pdfIn PDF document text
    • http://sandsflooring.co.uk/ckfinder/userfiles/files/tegukolirasujikofil.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/dc01947b36ca2e20415d3a0c6766cce4/99466408854.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/40791681684.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/42304894028.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/kurupevejavofuga.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/budazelajivadigiw.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/ics490gag495s54vv9mjlugsi9/27607491641.pdfIn PDF document text
    • https://tutorbolivia.com/userfiles/file/63204669719.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=can+i+use+firestick+on+smart+tvPDF 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_off0000de77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE77 10740 bytes
SHA-256: 4b386dd67b45912a1a514ecc7c1f1c94b412f1485040b2cb1c5485c9dc49ab73
font_01_sfnt_off0000f73f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF73F 17200 bytes
SHA-256: 21e1fd7075ad454b44b5eecf15f1c02dc23932292794eb29ac2e5f81c9038f38
font_02_sfnt_off000123ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1