Malicious PDF — malware analysis report

Static analysis result for SHA-256 12b4e4e1f1f93271…

MALICIOUS

PDF

82.8 KB Created: 2021-08-28 22:34:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 94e9f8bccf3be8a4d227a34246ee72f1 SHA-1: 08857a970b35aff0e228a947722517d9554e155c SHA-256: 12b4e4e1f1f93271b26352cfcc04ae3f4a25aa0fa3be895b4d4d6e2dd73eecea
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://articolo17.it/siti//usr/foto/files/48800368262.pdf In PDF document text
    • http://allaboutdowney.com/userimages/26029304157.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1625835845.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/39981615492.pdfIn PDF document text
    • http://feuerwehr-mittenwalde.de/mediathek/files/suwafofatin.pdfIn PDF document text
    • http://ferrocom-spb.ru/userfiles/files/peratonagujebogiwigob.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/zexokafefarak.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/93871789935.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/ob1h01vp4vs86b6ftj04ou0os2/lutalowape.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/17433270778.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/aca02261ddc46220d49f2c4fe55a7d5b/godagejugowimoxelesefanew.pdfIn PDF document text
    • http://fluorescent-training.com/file/47688956641.pdfIn PDF document text
    • http://hvezda-pardubice.cz/files/file/43690715156.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/15517020019.pdfIn PDF document text
    • http://hamyarsanatco.com/ckfinder/userfiles/files/tipinerudizidiz.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/ds0e68ggtfgkjceejlrs9gmksn/migidij.pdfIn PDF document text
    • https://kildevangen.dk/files/jasafukive.pdfIn PDF document text
    • http://exima.kr/userData/board/file/31353483896.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075ec4d32958---povulujejis.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210809163402167.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/rawilaboxefigu.pdfIn PDF document text
    • https://ms01bet.net/contents//files/36017307629.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=sapphire+plugin+after+effects+downloadPDF 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_off0000db2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB2B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f342.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF342 11160 bytes
SHA-256: f0164a2ca8f6168df02dd9622623cb25aa43248ab38db13f8488c12cfbd317e3
font_02_sfnt_off00010d21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D21 18376 bytes
SHA-256: 6cd116ac17cff5328dd3d4c14197e8b4c02304082b742e26715885a5f90c988f