Malicious PDF — malware analysis report

Static analysis result for SHA-256 71f95d9a913bcdff…

MALICIOUS

PDF

74.1 KB Created: 2021-09-18 10:15:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 41d00c280015f01e6d4c3bff854d17d9 SHA-1: 9075a7221f5c86adee529305c330a8aa1d67031a SHA-256: 71f95d9a913bcdff99914bcd10483d95a83829edaeeb06bb2963baed18604d31
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to external PDF files, indicating a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further suggests a malicious intent to distribute links, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://essaidafm.com/uploads/FCK_files/file/52748512741.pdf In PDF document text
    • http://bischofs-scheune.de/userfiles/file/simezezuduraxadaximawezog.pdfIn PDF document text
    • https://namhunglogistic.vn/site/files/35232399288.pdfIn PDF document text
    • https://alternativecarrepair.nl/userfiles/file/bofejenanilemavedagasis.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/42947886850.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/jefazofeku.pdfIn PDF document text
    • http://chuaphucluong.com/uploads/image/files/namogux.pdfIn PDF document text
    • https://mauspro.net/upload/files/rasusumomizofed.pdfIn PDF document text
    • https://textmakareknutsson.se/upload/image/30409134729.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/24069440908.pdfIn PDF document text
    • http://haustechnik-hagenauer.at/3406798635.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/11884088485.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/kokugodonikiwexomen.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/dalesavakalefowaxapisutel.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/35041402727.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/9299067976.pdfIn PDF document text
    • http://svadbavmoskve.com/content/xuploadimages/file/riwigiberutefaxuxurus.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/26719648553.pdfIn PDF document text
    • http://viprealestatebrokers.com/userfiles/files/82668101792.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/86552756926.pdfIn PDF document text
    • http://dongamold.com/fckeditor/upload_files/file/82540651930.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///92826710498.pdfIn PDF document text
    • https://themalc.org/files/file/10086659645.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=korean+swear+words+in+englishPDF 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_off0000be7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE7C 17392 bytes
SHA-256: 0b84056fb3c591d5cd44b542953656e6df5c289b14a7f8943f338582ab3d3c0b
font_01_sfnt_off0000eb5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010373.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10373 10504 bytes
SHA-256: db5a7eae4fc1fb255a464f3032ecf15ab212da9114cc705d9cda11124d9f539e