Malicious PDF — malware analysis report

Static analysis result for SHA-256 83cbee93db6bcb82…

MALICIOUS

PDF

85.6 KB Created: 2021-09-13 11:00:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 14d2e63a55d497e74ed13d5e487f7b90 SHA-1: 3463fd45351d8aa678cb55a24e81aa7e549fcc80 SHA-256: 83cbee93db6bcb823f42d13b8978b8ea516df2538a446c999d312714af0e79a4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that form a link farm, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of link farms on potentially compromised or disposable hosting suggests an attempt to obscure the final destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://sabresources.com/FCKuploads/file/wexixituvizigosakupuj.pdf In PDF document text
    • http://evevoyance.fr/adh/.-/file/17055202738.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/fusemokilugajeku.pdfIn PDF document text
    • http://enricobarraco.com/files/jawijazivuvidevumunurofik.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/punutipomi.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/c90251e7b7bbd28cf08e0ab7b7b2444b/bojizozexenakizudabe.pdfIn PDF document text
    • http://preiswerte-unterkunft-papenburg.de/mediapool/95388864796.pdfIn PDF document text
    • http://sial.pl/galeria/file/62557564032.pdfIn PDF document text
    • http://hangnhatbanonline.com/upload/files/48837673599.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/36309042890.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613e40fa543d6---50140508372.pdfIn PDF document text
    • http://faptvmedia.com/userfiles/file/40887735141.pdfIn PDF document text
    • https://fengshan-zhennangong.org/upload/ckfinder/files/sovivo.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/95106hqe6ct2t8o3gv28e54s64/migebaxut.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/4vecq9re7hkapl0p3gp7nhr91f/67402438603.pdfIn PDF document text
    • http://srs-budapest.hu/uploads/files/tikasikuvukolufakelaxepub.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc8dd86efe---2904371166.pdfIn PDF document text
    • http://chinahongji.com/d/files/74530178637.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/42549058198.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/dofeja.pdfIn PDF document text
    • https://a-metal.e-giant.net/archive/file/files/83078886951.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/lopomexexenebubi.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/79867717351.pdfIn PDF document text
    • http://www.polni.si/Images/files/sugatogazajavulakuzema.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=screencast+on+android+phonePDF 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_off0000ea35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001024c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1024C 10640 bytes
SHA-256: b87d86c639beb83b3f5a64148b7764f914536f3692a46ddd269cc603dd3679fe
font_02_sfnt_off00011a88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A88 17656 bytes
SHA-256: 37bc83e41d8a6906791b8bcc551a7118c6445c1c323e0e945b1cd92378bb3306