Malicious PDF — malware analysis report

Static analysis result for SHA-256 b73c69b643e9f0b4…

MALICIOUS

PDF

71.0 KB Created: 2021-09-29 04:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9253ad2e3cf8b083ebb7a9dccbecf1b8 SHA-1: 4d99eb5ca326b29fc2b30e2325781b2c68c88abc SHA-256: b73c69b643e9f0b44d186ec164417d0083eaec58e44b75e64fa3dea24df42e56
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Numerous external URIs were extracted, many pointing to disposable domains and acting as link farms, suggesting a phishing or malware distribution attempt. The document body was unreadable, but the presence of many embedded URLs strongly supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://laborke.ru/uplcv?utm_term=art+and+dalvik PDF link annotation
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/munifuzoxukes.pdfIn PDF document text
    • https://www.nstoplana.rs/ckfinder/userfiles/files/12478939955.pdfIn PDF document text
    • http://dietmoiquangle.com/webroot/img/files/lipajinumoxudovap.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146ebf567edf---41520833332.pdfIn PDF document text
    • http://abwingsmd.com/uploads/files/3100673503.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/jagasixivaxeb.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/70880285321.pdfIn PDF document text
    • http://dolonchem.com/upload/files/35945250587.pdfIn PDF document text
    • http://farmina.ru/uploads/files/44961041827.pdfIn PDF document text
    • http://dedanskecasinoer.dk/userfiles/file/gawajeretokabososibuxag.pdfIn PDF document text
    • http://kozelskadm.ru/files/uploads/files/jidukumafijazixowaboguro.pdfIn PDF document text
    • https://onecre.com/images/content/files/vowozilimamutarepim.pdfIn PDF document text
    • http://daydreamspin.com/userfiles/file/gomijuwojegikafefenabofit.pdfIn PDF document text
    • https://malinaionescu.ro/userfiles/file/doriwenakeladif.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/79028074852.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/46145444200.pdfIn PDF document text
    • http://cke.hk/userfiles/tawabapavuwesa.pdfIn PDF document text
    • https://pmms-online.com/assets/file/26697972492.pdfIn PDF document text
    • http://radis-rrl.ru/userfiles/image/gixolaf.pdfIn PDF document text
    • https://latgalesamatnieki.lv/files/file/67861945018.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/cv8qtht3t4dbdaa642e131u4u1/davevuwizedu.pdfIn PDF document text
    • http://westernmaki.com/uploads/files/sewosazuj.pdfIn PDF document text
    • https://taybaite.com/userfiles/file/46693698868.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/vopezijezetifikutag.pdfIn PDF document text
    • https://lapdonline.org/file/dogevagixelaju.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_off0000b45e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB45E 17304 bytes
SHA-256: 0e6db3f7f2ead5480c219dde262ce740afd20f61b08bd84a667472a95aab1cfa
font_01_sfnt_off0000e02e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02E 9960 bytes
SHA-256: 6e896e37bd69f5cdc8201461d9911ed4105f17a08a6a899da4f3f21afd294b5a
font_02_sfnt_off0000f645.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF645 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1