Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f04329d63dc25b3…

MALICIOUS

PDF

81.4 KB Created: 2021-09-02 19:19:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 0b2d60332561e44f91a2c57267304385 SHA-1: 4ccf071f65b26119e4cd8444fa1a56edcbff3f7e SHA-256: 1f04329d63dc25b3dd32e8b1cad049e252bf70bccf7401530413c502665da668
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external URIs, many of which point to compromised WordPress sites. This suggests the document functions as a link farm, likely for SEO manipulation or to distribute further malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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://primax.fr/wp-content/plugins/super-forms/uploads/php/files/n2abv5imdoq73uadkm7ucd6v16/5813299148.pdf In PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/ja2gopvm6naf8af6v32007s314/sizujexe.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a44a1fac0db---35965885478.pdfIn PDF document text
    • http://dragoniresorts.com/userfiles/13538054289.pdfIn PDF document text
    • http://gshosnab.ru/userfiles/file/tipesodosefagorenulukiniv.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/cpp6jjm5e32tglldrul6flq5f0/zavikegajaferunavi.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/94327252049.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/54979965159.pdfIn PDF document text
    • https://digireg.se/upload/jaravotosogubosipil.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/88526074204.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ef4phvjd6eu2s50ooooqsh7snf/pexiralebevexaratujelil.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/t0sh8jebuenkijc8bbo1h5ie0i/mopolajinigaxenan.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160c9a4dbae6a9---rakajodavelezo.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a1fbba7037b---zoziwo.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/402dfe9a57dd1dbc43b07b534b65ddb1/ketufejik.pdfIn PDF document text
    • https://shiphangnhanh.net/uploads/image/files/17903131871.pdfIn PDF document text
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/73290226309.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/tafamanad.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/linhkp0jmta4a52p2q9vcolc2j/52933177592.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/54951300558.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/jegoxikexulusaradodew.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609a09e568723---rasaludawagemafoxa.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/34942043694.pdfIn PDF document text
    • http://premiercontractinginc.com/files/file/tafegotolizi.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/bedanirakekezagumar.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/1mbm7fivhd1fn4mql8afsh1a0p/68072403551.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=civil+engineering+building+construction+book+pdfPDF 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://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_off0000db13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF325 16668 bytes
SHA-256: d318c9a82d2abed7674e4fe3d6ec4395eba3e6dfbc5d2a904223278bd957af82
font_02_sfnt_off00011e1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1E 11064 bytes
SHA-256: 01977100b1624538116dd4ba900a947b56ad68fc7d11eeb7b26708007c6e52fc