Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c91e6b3b693a8e9…

MALICIOUS

PDF

77.8 KB Created: 2021-09-13 19:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6d259b2b0d6311487ec9b097e9999b5e SHA-1: 7173114bddb21c1dbca81d543193bc43ec02d41b SHA-256: 0c91e6b3b693a8e9666a778b3bb066f7e7c8eba6da1d64d0a7fdb5a15d6fdcb2
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, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. The primary purpose appears to be directing users to a collection of other PDF files hosted across various domains, likely for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://szyoujin.com/UploadFile/file/20210901080734842.pdf In PDF document text
    • http://sziszolg.hu/editor_up/5682557030.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/52569561109.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613b35b947c23---zixodifudobeb.pdfIn PDF document text
    • https://pearproperties.in/userfiles/file/63018689791.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131b6f2042d9---44054323760.pdfIn PDF document text
    • https://inprovitcaribe.com/ckfinder/userfiles/files/tixokekawili.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/tisuzerudar.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/piwixafegujeb.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210913_233141.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210902121758635.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/24231745108.pdfIn PDF document text
    • http://www.beautyvogue.ch/Files/file/xapoveguxir.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/95737356429.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/jajidepagos.pdfIn PDF document text
    • http://edeins.com/userfiles/file/dimobiduzetitojop.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/meriginuwafepaje.pdfIn PDF document text
    • https://www.truckersplantparts.co.uk/ckfinder/userfiles/files/48592707909.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/piluteku.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/juwetivuwuvolitunuwulisen.pdfIn PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/zeserineperaxozezedopi.pdfIn PDF document text
    • http://fbrasil.com/userfiles/file///9616458021.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=world+english+3+second+edition+workbook+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_off0000c465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC465 19644 bytes
SHA-256: 1f01194342ad3c13346471205be24ee737c8cbcda5d056cb145c4caf1043da70
font_01_sfnt_off0000f7ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010fe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FE1 11220 bytes
SHA-256: 86ff3bcb45f9d26241720573ca69b44a7c1a9f443b36661e965de7fdccd8facb