Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b4b278630573c7…

MALICIOUS

PDF

84.9 KB Created: 2021-09-11 14:45:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 91df9b702bb9310d25249be82b204871 SHA-1: bf57a1da1ea606a202a2a041b2be43ea7afb925e SHA-256: 73b4b278630573c7cc42bbc484598770d12552c63f3312869a97257acda84076
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and utilize UTM parameters, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is intended to lead users to potentially harmful content or phishing sites. No scripts were extracted, but the structure and URL distribution suggest a malicious intent to lure victims through indirect links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://queure.ru/uplcv?utm_term=bike+trials+offroad+2 PDF link annotation
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/d88e39f73e7d724ae87d64f8a6797a5d/juvunakibojipezodase.pdfIn PDF document text
    • https://dancleland.com/img/upload/file/69958736364.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/renozeximomofarosog.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/41299028718.pdfIn PDF document text
    • http://sdds.be/userfiles/file/jipobuviriwolidijenubal.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/vetuxetuwoxa.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613912f01c44a---dinududitudakejuvo.pdfIn PDF document text
    • http://lighthouse-connection.at/myPix/file/35057469824.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2a63e4e61---lulenoro.pdfIn PDF document text
    • http://tongkhomica.com/upload/files/panivubupelixafemiwar.pdfIn PDF document text
    • http://daearesort.com/FileData/ckfinder/files/20210905_A55C53A116C81AF1.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/xivepulane.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/femikavomer.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdad12457a---komudanived.pdfIn PDF document text
    • http://fuerst-architects.com/uploads/file/32832024455.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/97993618877.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/daluwomog.pdfIn PDF document text
    • http://studiotecnicolamanna.com/userfiles/files/90169501551.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/diwelubavugapi.pdfIn PDF document text
    • http://boatmonies.com/uploads/files/derunexobitukema.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139cc99e5cdf---43237370499.pdfIn PDF document text
    • https://saptabangunmanunggal.com/indomobils/upload/file/guzaxuzifofuxajar.pdfIn PDF document text
    • https://elemental-ia.com/userfiles/file/93391383204.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_off0000e958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE958 10508 bytes
SHA-256: 0a0e78e71f9a09d5f49fb470777fda05936b17e565d43af0db351665e7e0ba3d
font_01_sfnt_off00010177.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10177 17216 bytes
SHA-256: f5a0e3ccd7277bd96fcb9beba1d5b7f021ed2a1d4025fd4e08f8bf24b6c0b3a9
font_02_sfnt_off00012e13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1