Malicious PDF — malware analysis report

Static analysis result for SHA-256 c334fcc45bdd3563…

MALICIOUS

PDF

81.1 KB Created: 2021-09-15 10:24:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ca43c65028ecf7132f430156413840af SHA-1: 3039c9b944ee41341256c691fa2cd44ee7a8bdb3 SHA-256: c334fcc45bdd35639ee6e1f6475a0026403f48a657504f7454aba00a4374b59c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous embedded external URIs, many pointing to disposable hosting and using UTM parameters, strongly suggests a phishing or malware distribution campaign. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=insta+ap+apk PDF link annotation
    • http://formel1vermietung.de/userfiles/file/71857048237.pdfIn PDF document text
    • https://vanrun-it.nl/userfiles/files/zaginubuvofowameledasapiz.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/16293148472.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/52149331279.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/pikabe.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109020901478577.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/37025672254.pdfIn PDF document text
    • http://mtt-association.fr/upload/file/2598401050.pdfIn PDF document text
    • http://iphonedown.com/ckfinder/userfiles/files/nusagogosidozexamajepeput.pdfIn PDF document text
    • http://bephoangdung.vn/uploads/ckfinder/files/fevetewogesolapenuk.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/jezesizorotapujubewu.pdfIn PDF document text
    • https://sydneystudytour.com/accounting/userfiles/file/lepinib.pdfIn PDF document text
    • http://eikenhorstgroep.nl/userfiles/file/tekewapeloxawulalote.pdfIn PDF document text
    • https://geneolock.com/locktactyuma/userfiles/file/6537483365.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/56734344354.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/fubezavikezidobofo.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b7c7b5fbf31bd7bcf73d3a2cefbb1f68/jumasozesufe.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/fibemagefaforapikus.pdfIn PDF document text
    • https://woodfur.in/userfiles/file/4661232314.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/62317599234.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/toxesokoxeraxa.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16135a564b9bcf---73379084359.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/81434709983.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lifisogonefakovis.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC6D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f47f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47F 17540 bytes
SHA-256: 2489a38068a7590357e098ae2005ae717b3ca5b9ca332739121072171f70dcc2
font_02_sfnt_off000121d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D3 9796 bytes
SHA-256: 22b4a0c52c036e628fe371f3197a937af8940c917534cdb7da4f36b705170e05