Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd53f1c5cd361f33…

MALICIOUS

PDF

86.3 KB Created: 2021-09-05 04:49:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d71419d297989d7e0f760ad664d76c60 SHA-1: 643fa0849512ed773d7223497251b46f29ff1644 SHA-256: cd53f1c5cd361f33a4cf1d24639209ecb11d3b1b2621a63926313123b85d5734
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Several heuristics point to the document being a link farm, with many URLs hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the nature of the PDF and the presence of numerous external links suggest it is designed to redirect users to malicious sites.

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://dukra.sk/editor_uploads/files/98035425883.pdf In PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8de0f2b7c---tejarabuxidasomuxasikad.pdfIn PDF document text
    • http://vpecargo.com/userfiles/file/63058544384.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1622861510.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd0481b383---botina.pdfIn PDF document text
    • http://shadesvalleymounties1969.com/clients/868959/File/defuxedowuxi.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/xawazobobagazidalat.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/wudul.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/fofisale.pdfIn PDF document text
    • http://eventechsite.com/files/files/daguzo.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/253f4abe3d262ff9e0c88a741cbb8463/lunipupigojap.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/a6f55a931fb999bed8071e8b2c432c86/58376063119.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcfc4897d09---nazapudeselag.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1610702cc7a9e9---katapavupevuparipikefave.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16083bb2531fd9---mimikegevizunot.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d508c131ee4---70920590359.pdfIn PDF document text
    • https://betenagro.com/sites/default/files/file/43412817369.pdfIn PDF document text
    • http://xn--42cfa4ewb0a0b3fwh.com/imageupload/files/dipupoxojizep.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/8f112d36f192175cc52b971a0293a98c/fojopemavulufezudixib.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/sosaka.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021071908413470554.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a140ab61910---pemulagijama.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bca109bd74d---98702057680.pdfIn PDF document text
    • http://cabini.it/userfiles/files/wiboj.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/1420829939611034208924b.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=terapia+cognitiva+de+los+trastornos+de+personalidad+aaron+beck+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_off0000e9cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CF 11056 bytes
SHA-256: 2d6424bec908c7db93827fbd646bd8f05b5118f1d4ed7543695a2899a882d33f
font_01_sfnt_off00010346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10346 18540 bytes
SHA-256: 656e14a12db2b5b379d3b54bafec210a4fe49047af8c35e30c162f4eb1c1d2e1
font_02_sfnt_off000132a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1