Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d35e5d16feb3d0…

MALICIOUS

PDF

72.8 KB Created: 2021-06-20 01:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: ef47cdb7a5c5c8a82712dfdc3cd00d2c SHA-1: 04d7a794cb446514791f5e35c7eab6e8676cfca5 SHA-256: 31d35e5d16feb3d0efdff7f8c7c653ee16e17afe74f6ad34b750afc3a587e284
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, designed to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the presence of numerous links to PDF files on compromised domains suggests a downloader or phishing campaign.

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://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160af9f74cc393---nutenorixiwerubob.pdf In PDF document text
    • http://yakutiaprime.ru/SITE/files/editor/file/kibimoban.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1608acbb2edda1---doravilute.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2273bf8ad---88603874436.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/024381fd3db8ee9dfb644b4dd714ce8a/sisalewezufapevegoxuvum.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/mewafu.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/42557192297.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/80494079074.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/3318e8d7070a830443d3825fe2703c87/modesoxazizexe.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160838054ea69c---9630030147.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d81fead8fd---nidogirunuxufawugimowaf.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608b26ee5f39d---30126148112.pdfIn PDF document text
    • http://mientrungpetrohotel.com/users/files/minabawagizonigi.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/1fd20e1c181058f00113e931c965fa2c/gabotipekulajabi.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607afeb1b9b47---40704132552.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=hum+aapke+hain+kaun+full+movie+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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0000fc9d.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xFC9D 16836 bytes
SHA-256: 4417915e9ac414fb4434340ee592f6c3e6ddbcde9a85fb5d6836220e79849cc0
font_00_sfnt_off0000c4e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4E4 5280 bytes
SHA-256: 0f9b5737f0d766a06ca1f0ffe961bc3c52019871364af04593ecb4550b0a5d0e
font_01_sfnt_off0000d6c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C2 11040 bytes
SHA-256: 12d6115ccf2725354190621ccbf52f70a6627361daad8110aa7a6b4e898f496e