Malicious PDF — malware analysis report

Static analysis result for SHA-256 b351dfdf839cbefe…

MALICIOUS

PDF

81.6 KB Created: 2021-09-05 15:25:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 45b4f6aa3697c7095d3206e4cdeb96d3 SHA-1: e1b4d6ca5815651a0b06367ff8fc230b5c6d4ca8 SHA-256: b351dfdf839cbefe1f812a06b290d253be9e244b1e05ea28e4526ece5deff5fc
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The embedded URLs, while some are marked benign, are part of a larger pattern of redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://granitnet.hu/editor_up/77745513069.pdf In PDF document text
    • https://akapacha.com/userfiles/file/27753699658.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/viwarenimupedog.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/1080736684.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/garikamakojokevigerij.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/37418949579.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/s24uvkdutu85gvso7rihst273f/rovon.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/94216672787.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0b0819277---1324992133.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083ecb5e9e0c---60862544206.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/21d72f376da103924526f9380dfba897/58802385903.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/97442794403.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/99811078f7c3dc787f9574b9b837fe7e/darinofaxawijulefujo.pdfIn PDF document text
    • http://jhsclassof63.com/clients/c/c8/c8cc7cee7579ddcd469b669c0eb172d8/File/2460318544.pdfIn PDF document text
    • https://relans-nn.ru/images/docs/file/36062550316.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c977d4c64ea---14354234291.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=international+standard+iso+9001+quality+management+systems+requirements+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_off0000d936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD936 11492 bytes
SHA-256: f8daee00ba61486d14fd3fab20178d312fa36e65adc08b50bb0d45a4a0819e67
font_01_sfnt_off0000f3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F6 17516 bytes
SHA-256: caf20a137c66168200449ab19e12a1dfe6265c26542b4816237cfd656292b0cc
font_02_sfnt_off000120ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1