Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c447aae1fcef7e…

MALICIOUS

PDF

70.8 KB Created: 2021-09-29 12:22:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f458a0592ef1b6e083f87f09ac7564a1 SHA-1: be63d9ec33a4de068d006c238179e4c5e5ef4082 SHA-256: 81c447aae1fcef7ebf4535ea74b92decab807d73418c2a3a2790f9bb7a0615a8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to disposable domains and employing UTM parameters, indicative of a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to redirect users to malicious sites, potentially for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://pistant.ru/uplcv?utm_term=fortnite+action+games+android PDF link annotation
    • http://hotelrealerimini.it/userfiles/files/kusipen.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/75969227750.pdfIn PDF document text
    • http://tiquital.com/documentos/file/57047229588.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/92727851864.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/finak.pdfIn PDF document text
    • https://o2opr.co/userfiles/files/pomafa.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/remexetinatobo.pdfIn PDF document text
    • https://pacpartner.net/images_client/imagesfile/87445143295.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/69354428058.pdfIn PDF document text
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/mubomexoraniluz.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/rubedetolo.pdfIn PDF document text
    • https://kotypsy.pl/ckfinder/userfiles/files/seminib.pdfIn PDF document text
    • http://dirpub.org/editor/ckfinder/userfiles/files/kawonekosuxagalerug.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/sositikikojebamitipux.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/5254267763.pdfIn PDF document text
    • http://kantipursecurity.com/userfiles/file/25382485110.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/e09lvej9ufd802nlcbcba362as/bulukimusiliwija.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/kujosolivuditexugulotil.pdfIn PDF document text
    • http://traktor-tv.de/sites/default/files/file/kidipibatasexutuwil.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/46194829448.pdfIn PDF document text
    • http://klientskazona.radeton.sk/ckfinder/userfiles/files/30066728713.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/totupurunogifiji.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/jekonafefufate.pdfIn PDF document text
    • http://cluster006.ovh.net/~greeters/be/ckfinder/userfiles/files/99557500041.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_off0000b1ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EF 16616 bytes
SHA-256: f6a193f4b6948e5b0b0fb7928a247c965d6798a021370db664e1757c1a768047
font_01_sfnt_off0000dbc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3DF 10644 bytes
SHA-256: 3b44ba8dff622831845428de50203057946f068be25530631e006512bc6315d5