Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c400975af2674a…

MALICIOUS

PDF

83.4 KB Created: 2021-06-24 05:31:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: ed54d177baf188b925046fe16f07bd05 SHA-1: 24399d49c1cc8d09feb7242ce480eb32400b0583 SHA-256: b5c400975af2674a6827a465650b26a8f8cc5e441cb4e64654c96a68c762b949
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links, many pointing to compromised WordPress upload directories and other potentially malicious domains, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, contains keywords related to 'automatic expansion valve pdf' and 'wkhtmltopdf', likely serving as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://fontanarosaserigrafia.it/userfiles/file/zutibilovoju.pdf In PDF document text
    • http://weberstellen.ch/userfiles/file/27472885050.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd6d799c7e6---17964615593.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/figudijobokitorakagekuvog.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/97165528613.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/ke9aj7eriog60evi5ttcts5ot3/30564625411.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce680ea387---pakerovikubegusuveja.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608873ffcf964---milevo.pdfIn PDF document text
    • https://777mto.org/contents//files/60724087600.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/4de573324ec673e5ab4c9e4f7c34a4b2/58224384047.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/b197afe1a568bdcf701d3e9c79ca8f18/78535572629.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b4c7bd927---vanusododulaka.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/79803211421.pdfIn PDF document text
    • http://aweibel.com/Photo/file/13529674996.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/81413539420.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/1733niv8odm9o3eugojmr55qhk/26398483277.pdfIn PDF document text
    • http://burattinojatek.hu/userfiles/file/sobojuzev.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=automatic+expansion+valve+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010a71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A71 5324 bytes
SHA-256: 685ff66b152a5bd1f0c9488942acdd481b9ecd9415413c64799bdacbb587c5f0
font_01_sfnt_off00011c83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C83 10696 bytes
SHA-256: 51246c65b25885249f48fb1812ae039482c55d549fc9622e4243a3ad7c2cb2e7