Malicious PDF — malware analysis report

Static analysis result for SHA-256 57cf4b97b8bcac06…

MALICIOUS

PDF

73.2 KB Created: 2021-09-07 04:17:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ea0a8ebcd0994a5a7e9076ab989eef13 SHA-1: e744ef45c58c17d894231b4661efb7103a25c492 SHA-256: 57cf4b97b8bcac066b10860f43cb403a0c5437c3c3bc5b971143020b532bf9d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the PDF is part of a link farm designed to attract traffic and potentially distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://foto-preiss.at/upload_files/files/liziguzakegop.pdf In PDF document text
    • http://littlepearlbooks.in/data/eimages/file/fupubetajife.pdfIn PDF document text
    • http://lube-stc.com/ckfinder/userfiles/files/sufamemiz.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/58346264906.pdfIn PDF document text
    • http://ohdiabo.net/images/ckeditor/files/wajukejasixupewilubowu.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/rimezivixexajixetoruvuj.pdfIn PDF document text
    • https://limblength-sldf.com/userfiles/file/96594232862.pdfIn PDF document text
    • http://studioarchoggianiepartners.it/userfiles/files/benevifibiganu.pdfIn PDF document text
    • http://pajurioverslas.lt/ckfinder/userfiles/files/95819202929.pdfIn PDF document text
    • http://www.lasallelille.com/admin/ckfinder/userfiles/files/615288483.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/25f3724f34735847728e2144cb11fbfb/bebolozemelej.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb8ebdc1a5---wapowunujizovase.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/mimcj4h38hrffvrdardc7v6jid/3993151412.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/1d3ddddd73366a9fcc16e2b0b2ebf79f/damaxezoregekidek.pdfIn PDF document text
    • https://rosycaffe.com/file/73281127699.pdfIn PDF document text
    • https://ccskin.com/geektic/files/likezuro.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/dinerutomuv.pdfIn PDF document text
    • http://mbjarrahi.com/UploadedFiles/New/file/zagugivonekumosekax.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608088d7c4614---25044559282.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/loxogexaturedibizesif.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/24202015872.pdfIn PDF document text
    • https://vasantviharproperties.com/userfiles/file/64408876782.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/80092744478.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=convert+image+to+pdf+pcPDF 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_off0000bc29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d43b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD43B 16484 bytes
SHA-256: 6d3c6ed59e0bc18da36d665a8cfd9a0977421f336b79509116401520dc099542
font_02_sfnt_off0000fea2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA2 10844 bytes
SHA-256: b6220102ccc6fc5c2c093dff9c3f3b18850a364d772e374345632cb17b8c0cad