Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a8b88727151eae8…

MALICIOUS

PDF

84.3 KB Created: 2021-08-18 04:51:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 409399ce5b3f6f564aaec4446386c1e9 SHA-1: fac15c6a59edfb9c2284ab0264ff4f03c6f78a5a SHA-256: 4a8b88727151eae8aa23b5b30a8c87838ccf98f0e9e95fa9c93ecf1eb7d7b72c
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure and link farm nature suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d8c7a5aa7fe---26710436370.pdf In PDF document text
    • https://chmelo.hu/sites/default/files/file/biwudapox.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/kujagafovumugabimowejer.pdfIn PDF document text
    • https://tch.lu/files/files/loterajatopij.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/2820453123.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ab79da544---76424518982.pdfIn PDF document text
    • https://dunaweb.co/bg_image/files/99193239681.pdfIn PDF document text
    • https://maintogelonline2.org/contents//files/6649300550.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2a3cf0a5e---dilikabepiwudanapava.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a6414ac48---fizusofebo.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/9339914826.pdfIn PDF document text
    • http://papianiarch.it/userfiles/files/moxojabata.pdfIn PDF document text
    • http://inoxbienhoa.com/upload/files/gatenaxa.pdfIn PDF document text
    • https://beyondpins.com/calisma2/files/uploads/sukebazonegenagonafef.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/14138a691bb637de03a911e8181de5ac/boworobavimerosafe.pdfIn PDF document text
    • http://geo-equipe.it/userfiles/files/zuxorepuwoze.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021050215404973499.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/sepemenapovoxegabiges.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/sofefopok.pdfIn PDF document text
    • http://rentaruedas.com/files/others/58758624835.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/953ae2ba5e05dc4063e9af94b58985cc/9785948307.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/1df741a1ac91f2d4226d82bd058cf2e2/govaxezefaxa.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb4241a0a01---vozuxom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=budget+worksheet+excel+free+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_off0000e1f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F1 17200 bytes
SHA-256: d9ee1fb2b67837bca0319e62a957b2fe411e85aeb15d5b9c37a3a26631468459
font_01_sfnt_off00010ee8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE8 11096 bytes
SHA-256: f6d3583dd08bab809cc2669dfb8ce038f651cb5a1a795a4ff27ebc871e8b5125
font_02_sfnt_off000128af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1