Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7a7361b32fc64c3…

MALICIOUS

PDF

131.7 KB Created: 2021-06-24 13:37:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 023acb67589e9ab2f6eab513b4c2f489 SHA-1: 28d134cfc76ec2990ee6a92250de689a1a1e1b32 SHA-256: b7a7361b32fc64c39783af579b847a531c03df9af5afc5fa495591fc047fb075
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file, identified as malicious by ML classifiers and ClamAV, functions as a link farm. It contains numerous links pointing to compromised WordPress upload directories and other potentially malicious sites, disguised under the pretense of 'Spelling practice book answers'. The primary attack pattern involves luring users to these external resources, likely for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://szekszardportal.hu/userfiles/file/vabejerarigididexomebumi.pdf In PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/2fe75da9891a8e47e621d3002b0027d4/63273985096.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160871f88a5ab5---sawimosiripefe.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160827fb42ac04---32929847837.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/jqb8b78cplviqg1qvmi2r4ogq6/wojuxa.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/57432dd1fe9e3c7d22ecadbd8e3cee93/36670206740.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/suwoxaxilix.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/94308431320.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/91308495712.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/d054vji9n8oi9ff0sd37glg1gg/miwazogobatomero.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/28584633977.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/gagiwifepupusok.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b812f1ae3d6---badel.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d0b95d02e7d---22425828250.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/16084636537d50---nowinezenirofirakedexo.pdfIn PDF document text
    • https://associazionedynamica.it/uploads/file/xadopexojubuwujoxovumiwo.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/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=spelling+practice+book+answersPDF 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_off0001c80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C80D 5500 bytes
SHA-256: a6642d9aec5080e4681a04a8f66a872b4a068099d9a483cf95fc0392e815fa85
font_01_sfnt_off0001dae0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DAE0 11596 bytes
SHA-256: a266429aaef3d3b443a49fe9976bf353afacea67abdbf303229ef416e8783207