Malicious PDF — malware analysis report

Static analysis result for SHA-256 8321a3ec73ba7301…

MALICIOUS

PDF

77.8 KB Created: 2021-09-03 10:48:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 320fe228f90c44c2c615923276ebee2b SHA-1: 5358043e05d7c59cb8cb4183faad39566df98b6d SHA-256: 8321a3ec73ba73019956f263c9a063ea0526ccc95f458cb7c9470258d6751039
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The file's structure and the presence of many external links indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://pixomot.ru/uplcv?utm_term=calculus+early+transcendentals+briggs+pdf PDF link annotation
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/7sg2h625clffnceuf9fejrd3br/bibaliboxoxukaba.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b2bcc2b7f7e---lepuxavuxesosoj.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160941f501428c---42105850131.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/pdq0mcubecjbahvm56lmhqb077/vupakivezino.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f86690a08---44937239718.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/88363694985.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16077f0dd87351---39165374328.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/golunoteju.pdfIn PDF document text
    • http://schokozentrale.de/idata/62029139563.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a70f2c0d539---kezigozolurivofofudaduse.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c71dc49915e---76150483210.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c2bc9769911---zakozelukukigug.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/voxedamumixe.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/160ab41febd0e7---wonexojinesem.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/98837719811.pdfIn PDF document text
    • https://langestrand.se/anvandarbilder/204/files/26485831597.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/78085d753097f45cc82a664756db27d9/wixikojisiba.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160895fbba23e0---belekukaterojevilufeba.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/5f69f4f8099a5074572ed5936e2e0c90/debige.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e085fa134a4---fakogox.pdfIn PDF document text
    • http://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/c774a8d887c1de45b2ea26055044d9bb/gunesuf.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/zibotegovoteju.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f9376dc917---juneruvi.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/tefasinafirijo.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_off0000cbe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e3f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F7 11060 bytes
SHA-256: fd5cfb4263d4256ba5c988926c1ae72b5e57f2166e512b87c2dc0b53bcd54ab0
font_02_sfnt_off0000fd72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD72 16920 bytes
SHA-256: aa8a29712dd347cb02e6bd7b3939dc679aecd9f9a55c6f4310371522f856abff