Malicious PDF — malware analysis report

Static analysis result for SHA-256 73dfd57c79956a91…

MALICIOUS

PDF

68.4 KB Created: 2021-06-13 14:42:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 4db96d82a5ff92edbdb528838a28b3ec SHA-1: 2edd4c93a099b398d7d758a6f9832442c52f888c SHA-256: 73dfd57c79956a915d930c7c4dcbd4903bf844305d78cb38c371cd18c61a6bc1
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the exploitation of PDF vulnerabilities or the use of embedded JavaScript to redirect users to malicious sites.

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://coretry.ru/uplcv?utm_term=absolute+value+graphs+calculator PDF link annotation
    • http://veraschwemmle.de/fckdata/file/nevaxojizatanow.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/31225166497.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160963c1057088---gopategivafuri.pdfIn PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/b30d4cd1171396feaad7a2e9d013ddc5/68559689398.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210529092635.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/1608a07ed8e022---75919492170.pdfIn PDF document text
    • https://warungmimpishio.com/contents//files/46397467057.pdfIn PDF document text
    • http://cepsagibyachtfuels.com/images/photos/73962603447.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/csvqvojui145n6t669l3dtp363/lavivadiberaxemi.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/2326ccf61eb9ef02084624c9524eb3a8/44355218433.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/ruwetupiva.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/jhlqnga0cnjph8ftll9f7onmnd/23660132314.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a5f821405e4---fuzopimusagelave.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/13694046472.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16092ba17b56a6---vulaleturowexiluwux.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/dd51185f4735bbb9c902fc5c328363f8/73554179585.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/1051816985.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off0000cfe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE0 5384 bytes
SHA-256: 41970f71d74c0c598b72c29c95bab23da9a61473e5d47883878dfe0691f44785
font_01_sfnt_off0000e232.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE232 10084 bytes
SHA-256: e691e9a365a8970d5b2c4ae3115f45ac1a9238710d25c6ce08728b0172e975ed