Malicious PDF — malware analysis report

Static analysis result for SHA-256 dca0b787c4378bfc…

MALICIOUS

PDF

81.6 KB Created: 2021-09-12 10:44:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 02b847b286f644abe230623eec015826 SHA-1: ed8d2ff7cace2b710867b92ea2b26dcdc1d4b732 SHA-256: dca0b787c4378bfcacd69121147b1fc106fcbc4f11f68aa1fdde66035ca6adc9
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, specifically flagged as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress uploads and other disposable hosting domains. These links likely serve to redirect users to phishing sites or download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://yesilderecine.com/admin/editor_resim/file/xuliwerifupunujos.pdf In PDF document text
    • http://vocal.bpv.su/content/files/files/bovodakokikolovujaw.pdfIn PDF document text
    • http://bjxbw.cn/userfiles/file/92700376454.pdfIn PDF document text
    • https://woodfur.in/userfiles/file/97739145254.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613afbd4881e5---tunadinoli.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/87878086596.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/39454507472.pdfIn PDF document text
    • https://elmawadah.com/userfiles/file/mewedunididejazonuxozibuf.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/81951309997.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210911_013108.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/ruvaposadasisemakum.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/74610803090.pdfIn PDF document text
    • https://coevent.ru/upload/files/20027514914.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c064080e16---97468190304.pdfIn PDF document text
    • http://104408017.linker.tw/files/18537750939.pdfIn PDF document text
    • https://galaxy-training.com/userfiles/file/68044589318.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/phm5kh9k0hcbb06c16har47au3/pogomobukazo.pdfIn PDF document text
    • http://www.stemcellhairclinic.com/files/files/60141308221.pdfIn PDF document text
    • http://www.mediagrand.hu/data/editorfile/guwure.pdfIn PDF document text
    • http://nataliashishkina.com/userfiles/file/xoresefovekovavo.pdfIn PDF document text
    • http://herve-coiffure.ci/files/xuvawixolazazodibaw.pdfIn PDF document text
    • http://canadianrockies.ca/files/file/dutilate.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/13456207708.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=sync+office+calendar+with+androidPDF 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_off0000d9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B6 10680 bytes
SHA-256: 0eb50ffc369dc4a8b3fb56a314f840766113bd0e04c9cdbf01e2c01d19d4cc4a
font_01_sfnt_off0000f235.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF235 18148 bytes
SHA-256: 33a82f780e1262e37a217eaac4f2211a3de44cbe28c0d46fb062fd717a74cb57
font_02_sfnt_off000120f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1