Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c66e9e3768e6c82…

MALICIOUS

PDF

82.0 KB Created: 2021-09-23 10:04:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 09ffd551905751ce79265832f10db825 SHA-1: 447f47880ccc46972ae09dc47c6f4b1a98144a60 SHA-256: 8c66e9e3768e6c8258e9998d78f706194fd149c0ef18b1aa15c61b3b289c00b7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many of which point to PDF files, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links. While no scripts were explicitly extracted, the presence of external URLs and the nature of the heuristics strongly suggest the PDF is designed to lure users to malicious content or download further payloads, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cructi.ru/uplcv?utm_term=red+sun+rts PDF link annotation
    • http://panziofabian.hu/fck_kepek/39377426571.pdfIn PDF document text
    • http://sushifactoryazusa.com/uploads/files/munapevilejopoxabegejep.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/55883411972.pdfIn PDF document text
    • http://murito.fr/ckfinder/userfiles/files/tupexazozujix.pdfIn PDF document text
    • http://arucax.am/user_images/file/voxubosizexubajum.pdfIn PDF document text
    • https://dm288.com/slicice/file/4305506910.pdfIn PDF document text
    • https://bearings.vn/images/ckeditor/files/somakarevutuno.pdfIn PDF document text
    • http://choragwica.pl/userfiles/file/jumoxefuwuk.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/77681279525.pdfIn PDF document text
    • https://kaimano.it/file/77765173800.pdfIn PDF document text
    • https://mimpi1pusat.com/contents/files/4399506482.pdfIn PDF document text
    • http://prepearl.com/uploadsfile/wokagarebu.pdfIn PDF document text
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/perosupukiji.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/50084609000.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/42537866229.pdfIn PDF document text
    • http://thongthien.vn/upload/files/33737602551.pdfIn PDF document text
    • http://studiomistretta.com/userfiles/files/metafatedej.pdfIn PDF document text
    • https://meritumptt.pl/dokumenty/file/kozosagazonugesozuxex.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/netumufaka.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb0d47fa7---32319595066.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16315310888999.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614be46e4f073---42987258521.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/zasesukagigosoj.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_off0000df57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF57 9968 bytes
SHA-256: d1db3e266f3fb1ebd5232585043702a31dc7a6f885fb7ed7a77f29226adc9159
font_01_sfnt_off0000f587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF587 17476 bytes
SHA-256: 09a14b763664a87de081fb12c3e0a2803eaa9f074ae0273e6eb157c063874794
font_02_sfnt_off00012286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12286 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1