Malicious PDF — malware analysis report

Static analysis result for SHA-256 924f8a3b455bed3b…

MALICIOUS

PDF

75.9 KB Created: 2021-06-21 03:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 6fb4e5e9568d83f420eea68419dc06b6 SHA-1: 90645d76dcb57fe9123738be827238f87b271646 SHA-256: 924f8a3b455bed3be0a8df35776eba5a2977156e35a253034f72f1a35e04ab0b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

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://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5fae10c6a---lawolamabujarasadilal.pdf In PDF document text
    • http://entryexpress.online/chapter_images/files/wefebuvolevovexatadumipu.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac15e659fb1---5062580452.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a13e853cfb2---jutikiwegipijejijugogop.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/vuqhvvvcrl453n72d60j1hgspa/918740229.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/74802f904766e1310eb67e361dfd5be2/28430606112.pdfIn PDF document text
    • https://bouwservicewinthagen.nl/userfiles/image/file/jelafigafon.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/limuzo.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/sidap.pdfIn PDF document text
    • http://www.minaakshimajumdar.com/fckimages/file/28966000546.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/18584922527.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/87c90dadcdd95802be4907854191c668/wegisodepatixepo.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/jfrpmfv969tqfmnimcvtr3u0nk/8397011220.pdfIn PDF document text
    • https://satuldelut.ro/ckfinder/userfiles/files/talido.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/941e2ea0b7a9400f91739bd5652617ab/58041171024.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=line+graph+printablePDF 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_off0000df42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF42 4664 bytes
SHA-256: 002ba60f801f14e413e5355e094df1b0548e6c7c563d93713f37ed172b5195b8
font_01_sfnt_off0000ef05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF05 10732 bytes
SHA-256: f3544850a251922d3efcd7fa378ad824d6a9629145d9bef943901c7a25aaea1d
font_02_sfnt_off000113b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113B0 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f