Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ef0b3817fed18dc…

MALICIOUS

PDF

72.9 KB Created: 2021-05-15 21:23:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 6eb02f216ad1f5a682f5659791a5a66a SHA-1: 9417585f532ded45c93ea80395134a50782753fc SHA-256: 0ef0b3817fed18dcb14b7bf165ac12efc1cd0446cb755d69e526ee179666d63d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains references to 'Blue Cross Blue Shield Massachusetts forms' and 'wkhtmltopdf', likely serving as a lure to encourage clicks on the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://aftaplan.com/works/peepsparty/html/upload_files/file/15727932773.pdf In PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/5f5d1d1ce805f5636dd9d4aeb34a322f/zijakipuzekukiligovowob.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607244f94973d---gilusapapunoxi.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093dc53d4553---42391297507.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/0290f6902dc9e71da09f3aeb97d50b54/31121878012.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/b9d946a2289cf3015ac3d3aee9173a29/58587747518.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/f6d122ff349af2d7ba5c45bcc2562c25/82039910218.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/54e1bcf23b691c065c2740e7b6354683/tejuvatipusenuzob.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160867bf622626---33068502306.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/du6970dmesv6enek752bdi5961/lewebavenimijopibikedidik.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16072396958455---69258539255.pdfIn PDF document text
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/a667ee96093e2db0be6366a475b410b5/49383729535.pdfIn PDF document text
    • http://b2cexpressdemo.com/userfiles/file/godagutasor.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/9fb8ffa6e8d9efcde2af7154882bc12c/marebuwalizuniluzid.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16099d0f229117---24475617297.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=blue+cross+blue+shield+massachusetts+formsPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B9 5452 bytes
SHA-256: 3bcd30c1765712892a02fb6fea8c29d394b00831d3884cb50c7d69217ce496be
font_01_sfnt_off0000f310.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF310 10476 bytes
SHA-256: cbf4cde2366a4c567fa515d2b39b350631b58a7e2453bf69424a044e439e8cf1