Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a1d431627f4fd0…

MALICIOUS

PDF

71.1 KB Created: 2021-06-08 17:59:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 9104c5527b59a3f62037d46de4c17980 SHA-1: 2604a14e95b2205459a2766d82a12903ce28ecf3 SHA-256: c8a1d431627f4fd04a2c7d230624cf71227453eca361e25ebf28f267605d8f3d
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external resources, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the presence of external URIs and compromised hosting points to a social engineering attack.

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://laborke.ru/uplcv?utm_term=pokemon+fire+gba+download PDF link annotation
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0ed810a62---92414397438.pdfIn PDF document text
    • http://perfekttorun.pl/pliki/78251472652.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/fukonexaberepowod.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/fa8e48ecab63452e2809b6a08abe2f5a/voviwatolezorusuzowides.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a19fdf706ba---66114404155.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/mufikukeme.pdfIn PDF document text
    • http://penzionklara.cz/userfiles/file/39388968023.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/fuvugipidimajot.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210501005659300523250.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609dee2806547---92133992266.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8af95d636e---51153634648.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/monaxibunekom.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ab8e09d8a4d---fodiketud.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdb5c2c4fb---nulutikejanozedupiresexat.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/0459ad2bf98afeba20fbba7bd1799280/99643521625.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acdd013ed15---15479508522.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d42c0788b0---81366612276.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
    • 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_off0000cd5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD5B 5052 bytes
SHA-256: 49f2e7301127e30ac68489e96c97e9af56e51734e537d0653a6b04f18bcf9bec
font_01_sfnt_off0000de76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE76 10348 bytes
SHA-256: 5ca19633b0d58e401c9ac97bedb359b2eae2ed445532fb4d1e5f535ea805471f
font_02_sfnt_off0001018c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1018C 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378