Malicious PDF — malware analysis report

Static analysis result for SHA-256 b421a37acf227e14…

MALICIOUS

PDF

76.3 KB Created: 2021-09-10 07:33:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bf0e9c4ee5ea02f310b74249e88e896a SHA-1: b8202803bbb54fd857047c8573c6f791b803a166 SHA-256: b421a37acf227e14d77cb111848846dd566ef59a4c77347e3c8a4ee6f18ac162
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to various PDF files, suggesting it functions as a link farm designed to redirect users to potentially harmful content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://eminenceinc.com/userfiles/file/wixinonuladefax.pdf In PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/d452f7661533dc3b60e4d6d615c5b66c/gegupojemileduzofavub.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/vezosuboxukinabaviduw.pdfIn PDF document text
    • http://kirche-treuen.de/UserFiles/File/fosigeze.pdfIn PDF document text
    • https://dhins.com/testingsites/advantage_aviation/assets/media/file/73839861772.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/voratofojifuzeluk.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/guxowarotakaxelilanav.pdfIn PDF document text
    • https://nasikampung.info/contents/files/gomufiwomomoxilu.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/68937261587.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/30370424426.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/85091896154.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/43633552154.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/54019172178.pdfIn PDF document text
    • http://moristas.com/userfiles/files/toluzozagowadodixepi.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a84401d3b9---89811845753.pdfIn PDF document text
    • http://www.pantonerestauri.com/ckfinder/userfiles/files/viborumimasodujifowudona.pdfIn PDF document text
    • https://arerp.kr/data/file///24012050322.pdfIn PDF document text
    • http://thestarbusan.net/FileData/ckfinder/files/20210904_9C7250B9FA4535A7.pdfIn PDF document text
    • https://aznamaste.com/ckfinder/userfiles/files/2810469844.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/30232786667.pdfIn PDF document text
    • http://lifeline-sports.com/files/file/25904097480.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/98160867491.pdfIn PDF document text
    • https://campfun.myhost888.com/upload/ckeditor/files/18623204629.pdfIn PDF document text
    • http://freewest.at/39347746352.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=crazy+doctor+mod+apkPDF 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_off0000c553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC553 17880 bytes
SHA-256: 90575dadd52612ef85e89a2557c7b22ec28fcaa9435f46b0325810f38eb2e5ea
font_01_sfnt_off0000f411.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF411 10432 bytes
SHA-256: 3ba8d95cc471613bc975b9a8f0c7d7c7f80d3b2303aa378f822b003ac72c6806
font_02_sfnt_off00010bd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1