Malicious PDF — malware analysis report

Static analysis result for SHA-256 33835445b00ece7a…

MALICIOUS

PDF

72.0 KB Created: 2021-06-21 16:26:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 4e971f4206e0b373a2958522c45508eb SHA-1: fe768f484b5df12e9e4c0a243a4ec3ab36d819dc SHA-256: 33835445b00ece7a653e92a2fd2edc03ebf78ca9c1f0d6205091691dca4b0bb6
96 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was heavily obfuscated, preventing a more detailed analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcc34dbc89---94517676907.pdf In PDF document text
    • http://prinsart.ro/uploads/files/30645114673.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/s0rs0ce314mfs0hv46c7s6tuvu/96251899917.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/rapitizejigovoxikofad.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/40nimcnbf7ksh76boactjdnjg0/xudotape.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/70308354336.pdfIn PDF document text
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/c57d09129ad2a7f20767ecfb8b301108/rufudof.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/suwipedokofemif.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/b941dd1259e8b8050f0d678d65bac195/zabokusozoruxuxato.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-23/20210523152821479731.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/m0f9fttdtthd11mdkgd1n3fmu5/85756020794.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16085dda6ef87e---14789297373.pdfIn PDF document text
    • http://thegioidahoacuong.com/uploads/image/files/xuloruxobozulinoxadasimo.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/ad561bbb4b8edf925604e245024b62cf/88874932804.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/bototikavefediropizud.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/kiziz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=ace+inhibitors+interactionsPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC53 4984 bytes
SHA-256: 3a99b63a0e813b09753a9bd091980a01dbc2ae7fd86bc6b6bc5699193c790d42
font_01_sfnt_off0000ed40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED40 10872 bytes
SHA-256: 587bcdd0709a39b5e3b6d4df59f0ddecd669fedec8d09929e7d59a8e0fd2a78b