Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a6b58d8719a5f3…

MALICIOUS

PDF

93.3 KB Created: 2021-07-14 00:09:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 3ef17822cc90d9572c54690b773510a8 SHA-1: d1a67c5d5aa6526194ce049235f08b8f92113e34 SHA-256: 13a6b58d8719a5f3f8460fb3d12724bb3d7adca7174cd809af9e3bd18df5bcef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a common PDF-based lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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://crewmak.ru/uplcv?utm_term=loin+in+chinese PDF link annotation
    • http://adamlegal.com/userfiles/file/3551641646.pdfIn PDF document text
    • http://saokienviet.com/uploads/image/files/70910496537.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6413eb1dc---41987498397.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c06366c395b---jarilurituso.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aaeb927b66a---60585315628.pdfIn PDF document text
    • http://kidneytexas.org/clients/861060/File/xojifafudexip.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdb30372fc---kivikebakunexuvufiwuwowi.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf5f7859870---berojemerufufitufaxapodub.pdfIn PDF document text
    • https://robert-zauer.cz/userfiles/file/fudifanegenusixod.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095eda2d5cff---nobujevolorage.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/97530668310.pdfIn PDF document text
    • http://roycraft.ca/userfiles/file/49664121255.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/5968021834.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/hfmvq1kpobilactb8km5gfdkhk/zedujuz.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a85969bf5e5---7415596481.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/25702709817.pdfIn PDF document text
    • http://lhs60to70.com/clients/3/32/32806278e47d7e4d905c37b1d6ebf04a/File/58241097162.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/juxada.pdfIn PDF document text
    • http://immopolignano.lu/images/lukuziloxojevozawapu.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a50abce368b---61620569169.pdfIn PDF document text
    • http://score1forspencer.com/clients/4/45/4587145e2679cb7673d0e21b436e5c25/File/23616101731.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160b12897730f1---42811157363.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/0cb9b42f0b09d452aa3d2971beeb9197/44946855470.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/d784dn32ik46opudd5r69fboir/zenovugilimubutu.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160bb9f69a8a9d---21130257098.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10085 17728 bytes
SHA-256: 1287ef7cae3a29a88e2df4efdc418b3535320352b7f67398ad94b4d076c5abbc
font_01_sfnt_off00012efb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014711.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14711 9880 bytes
SHA-256: 921ad89cd05da1e8dddd58cab710652e5bd1c27a8d7f1215717956e6c276b050
font_03_sfnt_off00015ca9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CA9 2040 bytes
SHA-256: c9c99f1db4b7368340c819c7e7b91bef77ea8fd7890a85b92f47e41142b67c25