Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc557bff3ec0ffaa…

MALICIOUS

PDF

80.6 KB Created: 2021-06-17 19:36:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 1bf98d0e04b6107001f93cf9d9dfefa5 SHA-1: 772e99a5aecaf4e70ec252d2631574f48d14f5b9 SHA-256: dc557bff3ec0ffaa28dfc5e560bd9bb4b953c9c5a65e771bdeff15b4429fc261
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting it's designed to lure users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the rationale is based on the link farm heuristics and external detections.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/gd00tslp1e8149q889di4g8vgs/7540034988.pdf In PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/4558tdriru7d567833qji9e963/wepijak.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc9d8c11d5---81060037902.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/98991953329.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b66b913d34---80753139668.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091b916dc052---xetifigulenir.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/jp37876oju6bpurkglodiu39qr/84883248569.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/fofos.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/o6q8gkr5vap5f9ia1nens9rf8o/vixuno.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/3261895332.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1fa269949---60344956944.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/65052fddb131892b9a39b025e33cfc40/98886137692.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/b5ef737c9732ad937dd517be2a71f4c5/kemetigefiwalepisibur.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa17bd679cf---30899977360.pdfIn PDF document text
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/6484bb84277d0f3e87a64b4faae699e3/vobadeseduvovozim.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/~3/3vuEKuznOb8/uplcv?utm_term=sims+4+autism+modPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF405 5032 bytes
SHA-256: 1873678593f732eace4c42a0c8ee6074ff05e6e52f476c3ac8adba4779acd266
font_01_sfnt_off0001050d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1050D 2484 bytes
SHA-256: 8085e85f7ab2ec424f2d1e8603e5adaf13eeac0702cda241d6a7218dd8b8c71c
font_02_sfnt_off00010faf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAF 10800 bytes
SHA-256: 39e1d5664499e19caabd9df296231d44035c73fa9194370e7bfb21bda9f81978