Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff16d7a16ca5c810…

MALICIOUS

PDF

83.3 KB Created: 2021-06-22 13:56:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: d1856db67c297746ac276e1f585710fe SHA-1: 9c432fb096ecee4ae3b65ddbbb13cd0f2fa74786 SHA-256: ff16d7a16ca5c810e492570226921688357e1508c5bdf162d88d26d249474223
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised WordPress upload storage and disposable hosting. The document body, though heavily obfuscated, contains references to 'gta 3 download free full version for android', suggesting a lure for potentially illicit software downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://roweryelectra.pl/app/webroot/uploads/file/16219560731357.pdf In PDF document text
    • http://aihyang.com/userfiles/file/5016910371.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/ihuufi1uf4n2isb9da79mi6537/34400631846.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aba62ade2c7---zadigasoxowe.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0b58c7a82---xupawosaponekun.pdfIn PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/b3c9a8fb89119f41d3fe2ed1ef00d99a/tulawodadufog.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210526_27AEFEF2240054F0.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/de55ee0b86238549b464483ac59a7e0b/jiwivokisefima.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a0b881d6085---demumiru.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/vevofarupezipil.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/19336iblk85up4c8l2mqgmdi0p/doweginedawexoxusalesufeg.pdfIn PDF document text
    • https://tl-systems.hu/files/files/77812416913.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/81155750734.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/b299d7937609aed477f4c20123219235/runoxibikusap.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1e2bdb0bc---tekowibolefimebekezum.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070d09d2840f---11940093832.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/vugojilijozig.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/zamafem.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bc75521dbd7---jozifigusirojuleroka.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=gta+3+download+free+full+version+for+androidPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010a05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A05 5248 bytes
SHA-256: 1f2d1d9c07c31a56692c1f66b5f33678863bd0551d3c8963a7f649a865826d0f
font_01_sfnt_off00011c0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C0E 10444 bytes
SHA-256: b56192acf6ed06818a33e2279d567e5cdedd850df7d934e74df840485886dee7