Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e57dbc37741269d…

MALICIOUS

PDF

77.8 KB Created: 2021-09-03 15:12:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f1e929a47c9e4ee560b4970cfb1a76bf SHA-1: 0bfd2b91850acdf54994f6f4f76c414cd054a8ed SHA-256: 8e57dbc37741269d3d4394371db19b3a62cfd8c2a490c77388485431f60b644f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to host or redirect to malicious content. ClamAV and ML classifiers strongly indicate this PDF is malicious, likely a phishing or malware distribution lure. The presence of multiple compromised CMS upload links suggests an attempt to obscure the true destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160974a06ed6d7---53397941436.pdf In PDF document text
    • http://mebco.ru/images/file/13268280137.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/61af55247ce7eb554e5aa7aba0d8dcb7/60999197613.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/96066124794.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/sinolenujigu.pdfIn PDF document text
    • https://fanaf.com/article_ressources/file/tasawuwamefesedulupu.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/65315787499.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/hbtpv6u35im6vvpjosf03v9d40/24844618275.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d40d482ab7---satadetataguno.pdfIn PDF document text
    • https://alquimia.in/admin/fckeditor/editorfile/25436127810.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.fr/userfiles/file/41849498427.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/64308443362.pdfIn PDF document text
    • https://studioconcept-stand.com/fck_userfiles/file/60662600601.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/33f5a6f4e7b396e0a17f3d6853a9b023/lovaxuzefetudutupegi.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/gofexivuweto.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/donedomo.pdfIn PDF document text
    • http://lordbeaverbrook1973.com/clients/76835/File/xuvesakefasazexe.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b01da2cf86e---44262741705.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160745c85b416a---8682820816.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/xubosofe.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160834e21383d9---66884186715.pdfIn PDF document text
    • http://izumrud38.com/ckfinder/userfiles/files/zemitavugomulezekefagoke.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/67426593987.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=nhs+portion+sizes+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_off0000cea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA9 10424 bytes
SHA-256: 56f957556f33d5fe47a1c12783ef5589487f82ada8f918470b50da7a89d551b7
font_01_sfnt_off0000e63a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE63A 16920 bytes
SHA-256: 10c870cf4a2a4073bac9f30944bbf32c26612b6f44c0672985c4a9b7b1d5fd03
font_02_sfnt_off0001121e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1121E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1