Malicious PDF — malware analysis report

Static analysis result for SHA-256 a510400299a5fda4…

MALICIOUS

PDF

85.5 KB Created: 2021-09-13 09:29:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 023296714be2c7b86cb108bf0bba4aeb SHA-1: 266e4ff098410ccaa8999fc4d16072f6eaf9bc99 SHA-256: a510400299a5fda4ec24969bdd59d518478b852d1038db997b94e1ead717c437
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external sites, many of which are likely part of a link farm designed to obscure the ultimate destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the PDF is used to distribute traffic to various potentially malicious or phishing domains. No scripts were extracted, but the PDF structure itself is weaponized to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://smidgel.ru/uplcv?utm_term=fight+night+battle+royale PDF link annotation
    • https://hobbypet.cz/files/file/likarasadigivokutepavinip.pdfIn PDF document text
    • http://vkts.se/userfiles/file/geseminokadanivik.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/81178441341.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/zedakidafavuvumuketenorok.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/39139256378.pdfIn PDF document text
    • https://ximangcampha.vn/upload/files/puxefoze.pdfIn PDF document text
    • https://mkart.it/uploads/file/javorugepifomaxiresedo.pdfIn PDF document text
    • https://leresto-niort.fr/images/userfiles/files/11904541623.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/vimejodugoxigi.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/tinazoludureda.pdfIn PDF document text
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/runivawuvefogasevorazit.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/jelowebojonubaxomuvoteri.pdfIn PDF document text
    • http://lagrupacio.cat/file/7388481558.pdfIn PDF document text
    • https://erdemlerkoleji.com/resimler/files/futod.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/buvuxosukizevozatim.pdfIn PDF document text
    • http://astprom.ru/sites/default/files/file/69628230407.pdfIn PDF document text
    • http://jolanyee.com/upload/files/202109102018273761.pdfIn PDF document text
    • http://turningpointdigital.com/cote_dor_import/admin/ckfinder/userfiles/files/8779260992.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/mefaxafomufalagosupagape.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/xubuk.pdfIn PDF document text
    • http://hanlacsclub.com/ckupload/files/xosonujilinodowudibafeki.pdfIn PDF document text
    • https://igk-lilienthal.de/downloads/15605246419.pdfIn PDF document text
    • http://dtjxbpzx.com/filespath/files/20210912123238.pdfIn PDF document text
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/kalobojoxozuginukawi.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/16152928597.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8c74e45f0---85637310725.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_off0000e7c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7C2 10448 bytes
SHA-256: 582996992ad7546b8c791e2161ad08dd7f1788c0b7c75eaeeea503e37764184a
font_01_sfnt_off0000ff63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11775 18432 bytes
SHA-256: bb082ab9137e447e1e2360a65a1b0d4e114eb04e879c5b0096f39139d6729ac4