Malicious PDF — malware analysis report

Static analysis result for SHA-256 55a3e842522e1439…

MALICIOUS

PDF

83.7 KB Created: 2021-09-16 23:43:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e63d22a2291a7c1b96987d9b3c2ae6a6 SHA-1: b25d59ad7333bbd5c8620ddba3b7bde326e40e3c SHA-256: 55a3e842522e14394583449bb590c668307ea8e9d6707c53be4e12f6fdb0d3fd
66 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to disposable domains, indicative of a link farm designed to distribute malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is used for malicious distribution. The presence of multiple external URIs and the link farm heuristic suggest an attempt to direct users to download potentially unwanted software.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 4

  • 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://krisoc.ru/uplcv?utm_term=battery+saver+pro+apk+2020 PDF link annotation
    • http://techcessgroups.com/userfiles/file/61179944516.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/41258476910.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/32692337433.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/sabuvabegavipisosegekoz.pdfIn PDF document text
    • http://ozkayalarlojistik.com/userfiles/file/59010431198.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/58375566464.pdfIn PDF document text
    • http://foreverymuslim.net/home1/forevev3/public_html/foreverymuslim/upload/file/nelapupakuti.pdfIn PDF document text
    • http://podushka.by/files/files/timipufifak.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/lujuzunadirijawimokidesof.pdfIn PDF document text
    • http://sdtrafficticketlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lizagewumofafiwixix.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/46150345803.pdfIn PDF document text
    • http://maszyny.pl/userfiles/file/59258884250.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/99000279200.pdfIn PDF document text
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/59581706515.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/34885675321.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/36524633812.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/18615735110.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/nagigagabigutazufopiloniw.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16130eac36f2c0---69848153583.pdfIn PDF document text
    • http://bkdesign.ee/userfiles/file/tobegagobituriwifowi.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/polipemimurekado.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/jeter.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/73a96a67ebbb14f46fbfc57e198fa9dc/kusavizotidamuxinozagak.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/pesitomokufegarese.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/13618634455.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_off0000de62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE62 10568 bytes
SHA-256: ea2b83ac2dd26e5d8ee47c0a06c3c12eaad7e8388ec655b4cdc70d995a4653ea
font_01_sfnt_off0000f6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CD 19180 bytes
SHA-256: 49a103171d04a02be4b6ba9d49fae15efd75f4533ad78ae7fc4e73f9c1cf5290
font_02_sfnt_off000128d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1