Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5f8f154ac63cab9…

MALICIOUS

PDF

77.5 KB Created: 2021-06-10 16:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 2cd8b2ccc5d69201e5b8fdafb71d80fa SHA-1: e6e1f02b1256617fc9f9e2639cd1e991bde53324 SHA-256: b5f8f154ac63cab9e993a263f23f1046bee9e2d9417dd6a7a3ebb5fe4952211b
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake-CAPTCHA lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://drafthe.ru/uplcv?utm_term=char+botal+botka+kam+mera+roj+ka PDF link annotation
    • http://xn--o39a91gvwm83kbsn.net/FileData/ckfinder/files/20210609_DBD48FBB7BC045B5.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/15f6540707f5d42bbcb075aeee231d19/49024672687.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/5743f069aaf637cacc8d62f742698908/wugulusurojatuzugag.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607c98db56f31---bugetozutudexuzow.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16074723b6d92c---totujategiperulefusosupol.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078cd41d78d2---7509173190.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/442rdcmiuum9kgrnldg8nmhdb7/sofedugolutubopejonele.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/28112938547.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/iq6q483dn6i8hlbfm9psmo8d9j/98510793464.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/da8tb88tgi861k04nffrq09cla/52872418024.pdfIn PDF document text
    • http://rld-carbon.ru/file/fajaxikofutor.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16082faef841fd---78906371348.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ac97730c5fe---64480337985.pdfIn PDF document text
    • http://helloshoppingnepal.com/userfiles/file/todizarevox.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC53 4932 bytes
SHA-256: 0ff23b5bb972c970a125501f86a6061bc547f85c015677c87e4bc4632c8c526c
font_01_sfnt_off0000ecea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECEA 10392 bytes
SHA-256: f8562db737ebc0ccf4960c1b07b9cc2399a6d99cd520d72716642930da9fd666
font_02_sfnt_off000110ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110ED 6984 bytes
SHA-256: e8d0b470fcdf0aef465fa375ce4308cbce0d001ebe85c40dadae7f9a38cc9552