Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a3753eee65e3d08…

MALICIOUS

PDF

70.8 KB Created: 2021-09-14 01:23:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1584c0e378e00d9e0fb48b6bb9a2b861 SHA-1: 7de313c3dd16b284f760aa646a16bf4a1fc63f89 SHA-256: 9a3753eee65e3d0870f53ad49d0299c0f450e7dc749f0daa84488575695d6126
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for exploiting PDF vulnerabilities or initiating malicious actions. It also functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613674c8246a9---musovukamefulotok.pdf In PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-13/20210913220959603242.pdfIn PDF document text
    • http://bankerz.in/qpic/files/puxanixudijevuxaduden.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/sipegisepuk.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/8065574583.pdfIn PDF document text
    • http://hcm-invoice.vn/hinhanh_fckeditor/file/giwesimatudekerigok.pdfIn PDF document text
    • http://tc-muehlacker.de/data/tcmuehlacker/userfiles/file/ruziri.pdfIn PDF document text
    • https://gestionarival.com/userfiles/file/saxuzerifiw.pdfIn PDF document text
    • http://855solution.com/htdocs/cljr/data/files/95498347049.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/fa405fc5a8a933193153d45508bacebf/bigasu.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/23442475894.pdfIn PDF document text
    • https://wupaojichangjia.com/d/files/63822451447.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/38621125902.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210912_125910.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/88021585047.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/63eq069sjmi1iakfm5pt0cps7v/18663279239.pdfIn PDF document text
    • http://yunnanyingxiang.com/ckfinder/userfiles/files/kodaxovibog.pdfIn PDF document text
    • http://aktifithalat.com/resimlerfiles/15581303584.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/56568139675.pdfIn PDF document text
    • http://hoanhaochemical.com/uploads/files/4088008602.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/jusapos.pdfIn PDF document text
    • http://www.prctech-th.com/ckfinder/userfiles/files/lemig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=dmc+4+refrain+apk+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_off0000ae6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c67c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC67C 17736 bytes
SHA-256: b6fbf2985284d3283d8155c5ebea6f0aed70b250351b2ab03b2b768c1fad483e
font_02_sfnt_off0000f3a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A3 10772 bytes
SHA-256: 4db0c3dcfb75fac801183dc2c5142d6e27da71acfc81249a84db2a01dc4e500f