Malicious PDF — malware analysis report

Static analysis result for SHA-256 76de415c287495af…

MALICIOUS

PDF

95.1 KB Created: 2021-09-08 18:32:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: eb3dc9ba5e838b70e3f3f1e2040ba894 SHA-1: afabb57ef15f92819716d2f11b5ba0e24a162a28 SHA-256: 76de415c287495afc9b538e1186dc59c4afda9a01404b483f3ce6aae5b9020ec
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers 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, suggesting an attempt to redirect users to potentially harmful content. The authoring application 'wkhtmltopdf' is unusual for a malicious PDF, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://azstorestudio.com/uploads/files/90696467046.pdf In PDF document text
    • http://lejonhund.com/upload/33313320379.pdfIn PDF document text
    • http://daiwavn.com/uploads/image/files/zatozaxifimogis.pdfIn PDF document text
    • http://food-cloud.com/home/food-cloud/www/site/site/data/files/75851410416.pdfIn PDF document text
    • https://metrosecuritynepal.com/assets/userfiles/files/doborises.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210908165045256.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/70585749264.pdfIn PDF document text
    • https://goacetours.com/ckfinder/userfiles/files/fenowelolewixarozuba.pdfIn PDF document text
    • http://naturpix.ch/cmsimages/file/65944440243.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/webapunidozanela.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16136c66c16c8d---dalovogamezagijenunisuf.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/27625092197.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fef65955ad---14657683884.pdfIn PDF document text
    • https://szaniterplaza.hu/ckfinder/userfiles/files/mitodesesikowevilegidare.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/12619726261.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/kaxibefelupal.pdfIn PDF document text
    • https://theptaynam.vn/upload/files/94601235317.pdfIn PDF document text
    • http://zhuoer.ltd/userfiles/file/firumanuwefopupases.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/91475487429.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/lokizamefawugem.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/nunadufuxafodulofimet.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/85664609892.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/31043190379.pdfIn PDF document text
    • http://ckattorneys.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kerumolijivusesif.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/seluvok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=lego+bugatti+chiron+instructions+pdfPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F9B 17564 bytes
SHA-256: c35ba62fe66b79eb18f20c28192ab82eaa734a8645db6ea9708e07a88d2aa2c0
font_01_sfnt_off00013d2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D2F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015546.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15546 11048 bytes
SHA-256: 832d5bf94f8a8f61fcb9d72620edc804fb49492632dfb7071e935a904fa3fd87