Malicious PDF — malware analysis report

Static analysis result for SHA-256 f42d5b831a3b062d…

MALICIOUS

PDF

79.4 KB Created: 2021-09-22 15:55:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 28e56f39e6a6408cb64625588939a562 SHA-1: ec3bad1ed57a5b4b88e5814cf986b845701325ed SHA-256: f42d5b831a3b062d924d34ed36249ae548040a4eef3ae295328585fc7800f89c
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute phishing content or malware. The presence of external URIs and link farm characteristics strongly supports a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://app0.linkeo.it/ckfinder/userfiles/files/gupemazazewagavarizepikeb.pdf In PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/1db6cd5b967dc36628d139172da448a7/bosunovataso.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/zupipunilolugixakeg.pdfIn PDF document text
    • http://prestopc.it/upload/file/43951818114.pdfIn PDF document text
    • http://aliguoriarchitetto.eu/userfiles/files/xekedijaposeviw.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139988a2af69---60348729020.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/30735638865.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jebezatugevujimagebute.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/98067833902.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/52022462582.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9faa79280---35063374701.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/36841848767.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/kubuxataj.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/feleridiwaxaf.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/bovexuvaxomewof.pdfIn PDF document text
    • http://noclegsosnowiec.pl/eurostyl/photos/file/neritovagodowutipewu.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/xigazamuvelun.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/bodijizurudafizedini.pdfIn PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/22405508269.pdfIn PDF document text
    • http://szwygs.com/upload/rezafavedixosisipeto.pdfIn PDF document text
    • https://theshamrockpublecco.it/file/marixizipoxujejat.pdfIn PDF document text
    • http://autokaryszczecin.pl/userfiles/file/ladigojuzapejoruzibita.pdfIn PDF document text
    • https://inprovitmexico.com/ckfinder/userfiles/files/62939722165.pdfIn PDF document text
    • https://kiofruits.com/admin/uploads/files/72277351992.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=fs20+free+download+for+androidPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C0 10556 bytes
SHA-256: ea37b11868ec690dc9da3afe98368f7c885dc6eab8c860f4fbd7afc973191d26
font_01_sfnt_off0000d105.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD105 19156 bytes
SHA-256: 1db92330db03eb31923a1bc22d3a4422a9b27a29d6bb84dcd947427a5fb85489
font_02_sfnt_off000101ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101EC 16060 bytes
SHA-256: 8bfc5e2f6383778b4716e60c732a7e5228106b692ca52c1f6b3c0b2892049825
font_03_sfnt_off000116ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1