Malicious PDF — malware analysis report

Static analysis result for SHA-256 4762538ad3bcb746…

MALICIOUS

PDF

97.6 KB Created: 2021-09-21 07:08:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2909865c5088f562e2da5262742464ed SHA-1: 2f5bc2367ced40867750f8b0e50ebe1d28c00436 SHA-256: 4762538ad3bcb746562e91cedd606748fad0df0ac07cc89513fd19ebab66d4fe
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to redirect users to malicious sites or download further payloads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm on disposable hosting, and the presence of numerous unknown URLs supports this. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://jinshi66.com/uploadfiles/files/jigapanafivufumigilike.pdf In PDF document text
    • http://saiprogetti.net/userfiles/files/73634285336.pdfIn PDF document text
    • http://sinorarechem.com/upload/files/tefoxug.pdfIn PDF document text
    • http://syntra.pl/userfiles/file/vafod.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/bejuze.pdfIn PDF document text
    • http://choinka4x4.org/cms/files/file/futiteke.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/lijisipeboxujiwewimubim.pdfIn PDF document text
    • http://sklenicky-obchod.cz/web/admin/fckeditor/userfiles/file/59403548162.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/zadojubupu.pdfIn PDF document text
    • http://all4pets.cz/ckfinder/userfiles/files/20753161065.pdfIn PDF document text
    • https://araprinter.com/ckfinder/userfiles/files/63211837655.pdfIn PDF document text
    • http://votava2.altrodesign.eu/ckfinder/userfiles/files/52069666256.pdfIn PDF document text
    • http://merklink.nl/site/data/ws/files/12842700166.pdfIn PDF document text
    • http://csc0532.com/userfiles/file/20210911202621_7accx3.pdfIn PDF document text
    • https://marmetal.cevhertemizlik.com/userfiles/files/5823672913.pdfIn PDF document text
    • http://nessie-vinylcare.com/file/vurixa.pdfIn PDF document text
    • http://feriaalainversa.com/uploaded/files/93759479525.pdfIn PDF document text
    • http://falcon.dk/sites/default/files/webfm/60876692935.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16134d9fc0af0f---14849488697.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/57762574103.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/75212953995.pdfIn PDF document text
    • http://sasmedm.com/www/js/ckfinder/userfiles/files/gefiture.pdfIn PDF document text
    • http://www.atsamuihaus.com/image/upload/File/kivototiw.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139968536fd1---segede.pdfIn PDF document text
    • http://cisseo.net/userfiles/files/junal.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/49448542540.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=actualizar+android+tablet+woxterPDF 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_off0001186d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1186D 10664 bytes
SHA-256: a75ebe63390b117f18ead4fa267093f1767633b591c4ba21fca865238a8a06c9
font_01_sfnt_off00013113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13113 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014925.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14925 18444 bytes
SHA-256: 42787b9c25026541621f955b79249aa33c481c5c16a1e0cae9535d47bdc180e2