Malicious PDF — malware analysis report

Static analysis result for SHA-256 5640a7de05275cf3…

MALICIOUS

PDF

92.5 KB Created: 2021-09-21 18:54:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a36935ec6829c410f558e26c6391ad95 SHA-1: 0a9ac22074d697197bb094526390333dd5323092 SHA-256: 5640a7de05275cf3ba4e7524d07db3e0cf9ed335f5868fd0f5fbb63fa60805e6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm. It contains numerous embedded URLs pointing to other PDF files hosted on various domains, many of which are unknown or potentially disposable. This suggests a phishing or malware distribution scheme where the initial PDF serves as a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9902

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://zilalcooling.com/other_files/File/80923382826.pdf In PDF document text
    • http://schokofontaenen.de/idata/80856189251.pdfIn PDF document text
    • http://sbs-group.co/userfiles/files/29529879284.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/jiwogoluvol.pdfIn PDF document text
    • http://business-plan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/13447949299.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb30c091be---26192577291.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/kanilekatemuseta.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/95001031350.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/wepukafigimexipetipodu.pdfIn PDF document text
    • http://winso.tw/userfiles/file/sosobososuminojel.pdfIn PDF document text
    • http://sumosushingrill.com/uploads/files/18041867404.pdfIn PDF document text
    • http://jobsandhi.com/uploaded_files/userfiles/files/43722227763.pdfIn PDF document text
    • https://mbbs.hr/files/878176867.pdfIn PDF document text
    • http://www.chubsorn.com/file/files/jaberag.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/wibevinabumusupo.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/lakegikidiraxita.pdfIn PDF document text
    • http://geriatriccarenewjersey.com/userfiles/files/45376894614.pdfIn PDF document text
    • http://studiobardinisrl.com/userfiles/files/tadivug.pdfIn PDF document text
    • https://babamansurkurhuseyin.com/uni/yuklemeler/file/zivenikizofubekalirinof.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/4b46ecfe60b851835a893dd8ae880f38/wetifikutijuzijatewev.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/13314450035.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/60762958638.pdfIn PDF document text
    • http://maudchristan.nl/ckfinder/userfiles/files/bakun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=d%26d+player+reference+sheetPDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D0 2272 bytes
SHA-256: e32ebda4fdf6ff75ba8d4d2fafa79540e9fd68adade4ca9f4ea587eb72372065
font_01_sfnt_off0000dbe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE6 16348 bytes
SHA-256: 8fcced7a8fcbf22d45689b44407ce1c1b45b78050135da208b7eeea4fc129b0d
font_02_sfnt_off0000f254.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF254 27940 bytes
SHA-256: 80577dbc1e004a2f92eb215cb12b6fc6368d832a19262e93ffbd8acba1f3cdac
font_03_sfnt_off0001388d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1388D 9076 bytes
SHA-256: f695977626623e59fedb2fbedebd468d0acf89ff6f6ceafeb3cee4351ddee6c8
font_04_sfnt_off00014b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1