Malicious PDF — malware analysis report

Static analysis result for SHA-256 421769a616aa7467…

MALICIOUS

PDF

70.5 KB Created: 2021-09-27 06:51:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: b901a75c8c9ebb102ed8e6f396718be0 SHA-1: f42b1f7b8bdbb58db7ab4a8d286d694e661912c7 SHA-256: 421769a616aa7467d5455e609d65ec53b7397bd52d2581e7b2f66103e1ea4f9f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL analysis are sufficient to infer the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://webaprint.be/img/file/18898238149.pdf In PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614efeb2392f9---79345635575.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/47780744983.pdfIn PDF document text
    • https://venus-forever.com/image/files/jupametuwafu.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/tidikedolojakibekaxebesox.pdfIn PDF document text
    • http://nationalcoopadvisors.com/userfiles/files/88263183933.pdfIn PDF document text
    • https://www.andreivieru.com/ckfinder/userfiles/files/vobopufalakowovalemusik.pdfIn PDF document text
    • http://criollo-cocoa.com/userfiles/file/nufarikokodomizerowililu.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131cf7180a7f---mefal.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/kedasisinazopugi.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/161454104dc732---99895702317.pdfIn PDF document text
    • http://skia22.ru/pic/file/gorakabomizi.pdfIn PDF document text
    • http://tomaszskiba.com/userfiles/file/zemotanuz.pdfIn PDF document text
    • http://getem.eu/files/file/56319545081.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/tear13dvmnvgtqcs2urvt2iod5/kigijalerafeg.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/2f61b20a30d9118a75cfc1ace66ed2aa/wakixononulojisut.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/wefowurodeluzadunopu.pdfIn PDF document text
    • http://kripasec.com/userfiles/file/80227395292.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210904_155121.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/xetoba.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/vojanilajexawixifupovapop.pdfIn PDF document text
    • http://oumkua.com/userfiles/file/gilurumolowuwatife.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/73412063415.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=einstein+and+godelPDF 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_off0000b074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB074 17596 bytes
SHA-256: 693f9a6de52a7a53bfeef72856c52dcdd36d60b063dfed6859fc557d24282374
font_01_sfnt_off0000ddcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCC 10304 bytes
SHA-256: 5e29a8de780f1006a96aab61146cacf72583eed4d3a5f2d942d10021d43ed9d4
font_02_sfnt_off0000f4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1