Malicious PDF — malware analysis report

Static analysis result for SHA-256 efd8fac04f37d674…

MALICIOUS

PDF

76.8 KB Created: 2021-09-06 20:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d88b7c5d074cb0d986260d886e007c36 SHA-1: da65b98cf4120c0dd58ca2110d23c9f46ba0fcb1 SHA-256: efd8fac04f37d6747a4e43d0782284c445d319a19732d2370dc20e1df89db058
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to multiple compromised CMS upload locations and disposable hosting sites. The embedded URLs, while some are marked benign, are part of a larger pattern of redirection to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/61af88a16c6cca43b65ec2fd5a878ee8/49144392790.pdf In PDF document text
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/4362001456.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/jogeji.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a54933dacec---25987833303.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b77dc4657a6---80225245704.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/271583293.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/7647996477.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afdc9b72270---20818609108.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/1189533184.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/8733de5ee8b1f11aa2bdc23ff64d7d39/kevipigasejexuwutab.pdfIn PDF document text
    • http://farashimirooz.com/files/limupuxogujenemix.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f23f2b195a---refupivujovimobopo.pdfIn PDF document text
    • http://cpils.com/userfiles/file/metitedizabadododof.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160762833021cb---mipulufunufipom.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/40da876253c9115f73dbc3ade930367e/rodutukakakabalom.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080fb6099b44---1089878627.pdfIn PDF document text
    • https://pypconsultores.mx/userfiles/file/bokala.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c49b66389---3291452889.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/8cc011f25c474706f794797fec1d470e/2214154712.pdfIn PDF document text
    • http://topstec.com/d/files/doxonameramewotesop.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/ruvuveriw.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/1e86e6cbbb3f0d17b9a82a1ba5184952/10032473650.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/ae1c0b88a1616a40dc35066069b96fc9/ledidu.pdfIn PDF document text
    • https://prospr.fr/ckfinder/userfiles/files/xasavije.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=grandstream+wave+user+manualPDF 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_off0000c25a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC25A 20120 bytes
SHA-256: 56c8add8fece23fcc5e97a00d74b1c83438443da60e2bdd117329032c442af6e
font_01_sfnt_off0000f5a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010dbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DBF 10488 bytes
SHA-256: 0b0ce248c276c3e48e9c052cc6949714dffa70202a37740f524e91743f97f4ee