Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad4c376176f6b9af…

MALICIOUS

PDF

85.1 KB Created: 2021-09-21 04:38:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5e8b58111a6001d4c5a8705c581c1153 SHA-1: ac9452a5960c34a29579332d09398da53efd4581 SHA-256: ad4c376176f6b9afaebd2efdc2b4c3a287d39ffc478901c5b1e7692db8441aa9
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised WordPress sites or disposable domains. The embedded URLs suggest an attempt to redirect users to potentially malicious content or phishing 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://catamma.ru/uplcv?utm_term=apk+droid+apk PDF link annotation
    • https://psychotherapie-coeppicus.ch/upload/file/50470902552.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/bemetaxotelevojatew.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/77916893940.pdfIn PDF document text
    • http://livilgirls.com/files/26068567471.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/6869b3402ba8a538fcf271e84b3db96c/97626568234.pdfIn PDF document text
    • https://www.ewdel.cz/ckfinder/userfiles/files/13075082805.pdfIn PDF document text
    • https://needlugs.com/userfiles/files/47912553431.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/948e16f7deb7895f641047807c187fab/77110239186.pdfIn PDF document text
    • http://thanhtindesign.vn/uploads/image/files/16585831022.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/15757791910.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/96659045657.pdfIn PDF document text
    • http://cserepakciok.hu/xdata/file/watogu.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/bd4f7056cc8f46fff680a2f5e0b95334/witubajejugufid.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/67827252589.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/punaguzaja.pdfIn PDF document text
    • https://e-ssuances.com/ckfinder/userfiles/files/modulazozezawup.pdfIn PDF document text
    • https://suruburi.net/mm/file/lijupeb.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/80142319936.pdfIn PDF document text
    • http://thermocomfort.ca/userfiles/file/fivogokidotimijiza.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/25325429671.pdfIn PDF document text
    • http://xn--b1adrijbbb.xn--p1ai/upload_picture/27077776325.pdfIn 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://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_off0000eb54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB54 17456 bytes
SHA-256: 1a6613b6010bb18e526c94ac71bd607bd6c2f10095cacf296dfa2e49a113c6a9
font_01_sfnt_off00011910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11910 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013126.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13126 9912 bytes
SHA-256: 832f6b903b430c984e9ba71876d36b730ec28817c9d3c41956597e2a7c1c9af9