Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc73bec51bf8fbb0…

MALICIOUS

PDF

75.3 KB Created: 2021-08-08 07:43:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6998a03d05642d72e78e41f0a6051392 SHA-1: 2eb6ebade730fe4794f4a178399e836356641a67 SHA-256: fc73bec51bf8fbb0b2a6243a7299bbda084ecc3e7ab0a788d4fa3e28b8d76e2b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for delivering malicious payloads in PDFs. The PDF also contains numerous links to compromised WordPress upload directories and disposable hosting, indicating a phishing or credential harvesting attempt. The ML classifier and ClamAV detection strongly support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c55d8c573e6---43568980794.pdf In PDF document text
    • https://mcdpiti.com/userfiles/files/2138053829.pdfIn PDF document text
    • http://dspec-car.com/js/upload/files/gebokisodo.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/wasepumavazugupug.pdfIn PDF document text
    • https://ymy-tea.tw/upload/files/muxodogepaje.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/files/60969312641.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160749700735cc---jaxudabikaxuwamun.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160946a85f024a---wikometipibeb.pdfIn PDF document text
    • http://tznjl.com/userfiles/files/17240597308.pdfIn PDF document text
    • http://kaizousha.com/js/upload/files/72003356094.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087f5bfac349---97970603290.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a3b633b3c---xesiseto.pdfIn PDF document text
    • https://icbacademy.com/upload/files/43270151295.pdfIn PDF document text
    • http://woori-tour.kr/FileData/ckfinder/files/20210802_20DBC9DB67445E84.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/lidozowufimit.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8746661fc---58647167156.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021053021001991.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/19acb1871c80edefab7061f4522353ed/zekodujalu.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/8a43e22ff3f05ca9e9be71388ba19631/diwadapopovu.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/b9f858d42a5a656609add65f1fa6d3d3/fazononejuwugotuzoran.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/63934301942.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fcc802a9c80---gebikoluda.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/dotenizitonugakuv.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/29695585916.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=kidi+secret+mot+de+passe+oubli%C3%A9PDF 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_off0000c160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC160 17224 bytes
SHA-256: e90555ae6647b5e1d6e6d267d1a4f2ae77d27562ddced755f2ae01052f111fdf
font_01_sfnt_off0000ecb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C8 10956 bytes
SHA-256: 34eb22d0f53738f265292735245512c2a7b9e8118fff956b9242d1c00bb238aa