Malicious PDF — malware analysis report

Static analysis result for SHA-256 87a14f103e865b72…

MALICIOUS

PDF

74.4 KB Created: 2021-06-10 21:21:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: cb50a3604d2f4b505b458e644a5e7a31 SHA-1: f82deed80a036b4110222d4edc560a4bd527763c SHA-256: 87a14f103e865b7278e17f1d235fe5c166ac74f9e9ab6966cf48dd71d94854dc
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious. It contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. The ClamAV detection further confirms its malicious nature, identifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/uplcv?utm_term=proofreading+marks+exercises+with+answers+pdf PDF link annotation
    • https://lepjunk12.hu/uploads/files/mugozawifiso.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160781d3e225c8---panokasojabij.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160779a57123cb---jopogejonojuliril.pdfIn PDF document text
    • https://giolog.biz/images/bulk_images/files/xiviwumobomatefovajonutuk.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/mhtigm90g4uq3tmtmbljnlt1dv/14263905401.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/92679a4bd1b6f4c8066ef11c458406bc/50920365109.pdfIn PDF document text
    • http://www.onlinetemsilci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a16d16a2db---fifumig.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/8709ffbb14244851e0899e28c1741a1c/xulozujom.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb6d826cb9---62443039661.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/18550286842.pdfIn PDF document text
    • http://dhsclassof70.com/clients/d/d1/d13f49183e6b2ef720c1f353b43de0f2/File/57358111825.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/dizevuriretizonoti.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16078c050df15b---tojaxebipefijes.pdfIn PDF document text
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/59620833118e6c2aadcb3c5db2689037/wofutanalavafawutefigike.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160824f050c3e6---bigimum.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/xosapiwigox.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_off0000e486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE486 5760 bytes
SHA-256: 7f56dbceac17f25546a1e9caa010cb42623a14ffbf1457bb62f9da20783404db
font_01_sfnt_off0000f817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF817 10584 bytes
SHA-256: cf529098ec0c6dc58dc7b2557825a3a180bb9d33f2b2550ff944e0022315f88c