Malicious PDF — malware analysis report

Static analysis result for SHA-256 031ceec20e4af504…

MALICIOUS

PDF

88.6 KB Created: 2021-08-13 14:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: abc158f00d9c0a12e9af80b1b942fe65 SHA-1: 3aa5fc9c8c1972c22f0db486ef8b43fbc23855b7 SHA-256: 031ceec20e4af50418de417e207080b3a7381c4240f908e48ee2839f6f4306b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a PDF link farm hosted on compromised WordPress sites. The document body is heavily obfuscated and unreadable, but the presence of multiple URLs, some pointing to compromised CMS uploads, suggests a phishing or malware distribution attempt. No scripts were extracted, but the PDF structure itself is used to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://geyikkimya.com/userfiles/upload/file/mejaku.pdf In PDF document text
    • https://bor-diing.com/upload/files/nevisazolog.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/rurfub2cs32j4d9nchqba74a2j/13509989420.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/seguto.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/77689809549.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/2d089099154b2a5822098c59c7fcfcb4/jigekekofanotafanoniw.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/musevukufenagivobudevi.pdfIn PDF document text
    • https://atraba-holding.com/userfiles/file/najolewujoke.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/64491069740.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/lexokolurebofemavemuweb.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/jovuzekunowuj.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210726155020_791345791.pdfIn PDF document text
    • http://orthopaede4you.de/userfiles/file/vefurudikame.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/k1ea0r5sntj4qngount4hbk13c/solijadusibijetemokisukaw.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094e7111b159---98010226299.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/wefesopi.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee636d3e8b---80568821774.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/24436694283.pdfIn PDF document text
    • https://reformedgeneration.com/userfiles/file/34195636737.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7a0980520---82775990345.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/wimuvazulowojamukeximuvug.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b601fb9c77a---vexugevexagegun.pdfIn PDF document text
    • http://totoquynhhuong.com/upload/files/52940855253.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d42936df1b---36686284419.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/livajiwobebup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=calendario+escolar+2021+bolivia+ministerio+de+educaci%C3%B3n+pdfPDF 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_off0000eef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001070a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070A 11552 bytes
SHA-256: 7723a02f0054717192cd50f99f146b5dc244ac3cdaf6274e0ec18cb8a53595ca
font_02_sfnt_off00012211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12211 18352 bytes
SHA-256: 550a5f547efa4de4864c72a86e4a6f5c821ba6c2a24ff62b523b9a4e526d8c0e