Malicious PDF — malware analysis report

Static analysis result for SHA-256 73613d222ba70a21…

MALICIOUS

PDF

110.8 KB Created: 2021-06-25 14:53:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 81f259c871085309243bee80c0a6b010 SHA-1: 90ce8d98d9b117453b74d52fb32baffe5aebdc71 SHA-256: 73613d222ba70a21c8a7159ec1e237c3d2b2ece8b365accea1d1f9df567ed07b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/91e63860a19e6793b93485aeb0d819cf/68904723205.pdf In PDF document text
    • https://kovosluzba-praha.cz/res/file/4972514115.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160919a9b548fd---25968325334.pdfIn PDF document text
    • http://verdantnorwich.com/clients/3/30/306756bb587dffcd11ca74610d845a16/File/venexijanosilif.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/gsqmmjfb31q63nrebiqmeh9v36/12754919597.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/605d115c1984b39d3d9cd3dcbea67fff/5085482388.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/22750304073.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095c58f21703---gimalorapinulaxarugu.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/zizaxupatarumexiri.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608af27498cd4---gigikitow.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/cbd890b2f8821b3579cb61f4ebce2d9a/25402585493.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/adc0b12749bcd5d2a5d187bfaa9ec597/49811566123.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/gawagoxebaxesoge.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16099d56391711---xepemavitagogubejupote.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160928a8938c65---16071322729.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c3f9a0671---39263631622.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=baby+bootcamp+moviePDF 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_off0001510a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1510A 10492 bytes
SHA-256: da69e08415c7d8b7c0888d8a61f4f5ef48361e4ddb98821371190f4c1104913e
font_01_sfnt_off000168d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x168D0 17712 bytes
SHA-256: f2c3dcf966396f728b13b017e30995e06173af8666ec0b51e5c4b1e3d8e6d732
font_02_sfnt_off00019696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19696 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1