Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b837f4440125b2f…

MALICIOUS

PDF

86.6 KB Created: 2021-06-13 06:21:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 021a6c6d58890cf3a2326300710333aa SHA-1: 30b27412ac23cf65c8e536b810e2f714bf463b6b SHA-256: 8b837f4440125b2fe0b7d101a048135fb4e7d3b78f2dda86dd889031545ac777
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document contains a link farm pointing to multiple compromised websites, likely intended to trick users into downloading a password-protected archive. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates that the document provides instructions for accessing an archive, a common tactic to bypass security filters. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://synerhu.ru/uplcv?utm_term=ender%2527s+game+speaker+for+the+dead PDF link annotation
    • http://thessalonikiflights.com/files/files/55631486424.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/125f41ef45f7067de7838d7f57bc2b00/biwiritagajigipunevi.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/argdjopo5d3pkf25l0nivc70l1/6109237608.pdfIn PDF document text
    • http://harposwebdesign.nl/app/webroot/files/userfiles/files/jegalurixebexonegajosolow.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c2f94f5fbe7---77654864572.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac12f0e685f---mudodokimewolidufum.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/82298227552.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc87a0691a---15544515640.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/1ckaf2b0vam50o1qkjl5h6el74/zorarulupusokes.pdfIn PDF document text
    • https://vietfun.com.vn/wp-content/plugins/super-forms/uploads/php/files/88egrfrenrg298jb61jrfnc0ps/94716184669.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/12a83f1119b9444553e18c6a968f53cd/butukow.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608b58141a191---67819872531.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/b78n02h4ukr472duqbr171tt8g/39132845870.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000114f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114F8 5476 bytes
SHA-256: 91426d048e6ed91cf6aa93f3ebc454f91db62cc516b6e0d59e5a062f3e0403de
font_01_sfnt_off0001277c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1277C 11140 bytes
SHA-256: e62e8da262be6dc390514fa8977c57036a23770ba94cc066ba0dc9d5a535adbe