Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c78c387ad97b455…

MALICIOUS

PDF

82.3 KB Created: 2021-09-04 23:00:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: da833a97c7a60f8d17db42fd2b061b14 SHA-1: b44c76e58038120b82492a7aa8ed7d439185c81e SHA-256: 7c78c387ad97b4554170dd7272420abbb003a28db5263d94d05b654df7e80482
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains embedded JavaScript and a link farm pointing to multiple compromised WordPress sites and other disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of embedded JavaScript indicates an intent to execute code within the PDF viewer, likely to facilitate further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/597820a51fe2add3a45177595ba906c4/kibokibirufowin.pdf In PDF document text
    • http://langeline.com/ckeditor/upload/files/jumisum.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/9a06f390d6642fad9c31541167670ffa/82071982902.pdfIn PDF document text
    • https://aldwalia.com/userfiles/files/19557745755.pdfIn PDF document text
    • http://agrion.org/upload/fichier/52086289456.pdfIn PDF document text
    • http://kiemdinhcan.com/Images_upload/files/4549230936.pdfIn PDF document text
    • http://hilltopperalumni.com/clients/9/93/936f23dc4abb03f6d4a1aae2c8a32781/File/41465628294.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/54d487eb7f39e9734fb45dfeb05ed890/31904899323.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a613f494ec8---9243649725.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/8178168667.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160daf088b95c7---makukuz.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/tipobujude.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/80668691011.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/pilawotoribab.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb648390c92---57736309262.pdfIn PDF document text
    • http://taketty.xyz/js/ckfinder/userfiles/files/53860616588.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/bamelabidetowekugesabas.pdfIn PDF document text
    • http://ps-chiptuning.hu/userfiles/files/sabaga.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/vopunufuwiwul.pdfIn PDF document text
    • https://www.vignolaweb.it/ckfinder/userfiles/files/zekexino.pdfIn PDF document text
    • http://scholl2021.com/clients/1/19/19bca4f76d5065ca3bffbfc1c67e7925/File/43334928676.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/181ab845c1749c6458b8d50e5aeb53ec/mavaxutoduvinibujumowej.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d3972b20a---25948615920.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=retorno+a+brideshead+descargar+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_off0000d9d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D0 19004 bytes
SHA-256: 62362fa615456d8d1cd2d663d447ea8a6389e0c8b4e9f54eed3226e866f4d498
font_01_sfnt_off00010a68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001227f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1227F 11040 bytes
SHA-256: 7b52c9e297eb215872136e419b69877cab1a836c0b5ec779b78074008534f1a9