Malicious PDF — malware analysis report

Static analysis result for SHA-256 5819ff14f31cb245…

MALICIOUS

PDF

79.3 KB Created: 2021-09-18 11:54:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: acfa921f6d4a63e9c7246aef26e214aa SHA-1: d8bfd076af0af4ed796e62f1d798ffef1c8795d0 SHA-256: 5819ff14f31cb245b5b605cd66e105bb79a9ed041009adf695c227da40df67a0
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 potentially compromised websites or disposable hosting, characteristic of a link farm. The ML classifier strongly indicated maliciousness, and the PDF structure suggests it's designed to redirect users to external content. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://2016.letnifestiwal.pl/ckfinder/userfiles/files/zukotugupijakeb.pdf In PDF document text
    • https://hunglivet.com/uploads/files/202109050201505642.pdfIn PDF document text
    • http://fruitvita.com/files/files/wajebipero.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/51371954335.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/wedotu.pdfIn PDF document text
    • https://hr-serdahel.hu/images/file/8169660888.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/8c12bd7ee41bf486e04c1d1680f23c8d/dexetaxode.pdfIn PDF document text
    • http://dienlanhtruongson.com/upload/files/80503269850.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/2445907203.pdfIn PDF document text
    • http://architettoletiziamasciotta.eu/userfiles/files/38170526415.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/wunuzonituwolavevubil.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a2b54bc0a---pufijiwesugobirezujefos.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161317bf97e319---pekux.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/nokav.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/95270981978.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/pajapenabi.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/2095298584.pdfIn PDF document text
    • http://avalon-essenzen.at/userfiles/file/komuminojirukikuwijalaj.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/161414a3522925---37183987989.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/kamebogobomewi.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/98591212359.pdfIn PDF document text
    • http://xtra360.net/campannas/file/16484344185.pdfIn PDF document text
    • https://stoneappeal.in/FCKeditor/file/mujofafeselomeru.pdfIn PDF document text
    • https://mimpishiodua.com/contents/files/wumimagotiginatin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=kooku+apk+downloadPDF 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_off0000d232.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD232 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA44 18220 bytes
SHA-256: 0d7900a2aa8284f009d235fe96d1ad767524c3c194b4ade474b88041c2c6f673
font_02_sfnt_off0001197c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1197C 10064 bytes
SHA-256: 415dd7f2d09b28c6adcc92edaae96953fe51f844b068135544adf31cfd12e69f