Malicious PDF — malware analysis report

Static analysis result for SHA-256 397b835cd0b9b8b9…

MALICIOUS

PDF

83.3 KB Created: 2021-09-12 00:04:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8762a1b30ac14412c861dafca293c7c0 SHA-1: ec70292ac6d86fafb252be0f12f5a71f797e6d50 SHA-256: 397b835cd0b9b8b92742d4f0a9940de4c87f0a9b024914511be8b4b8978de6f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains a link farm pointing to numerous URLs, many hosted on compromised WordPress sites or disposable domains, which likely serve as redirects to further malicious content. The presence of these link farms suggests an attempt to obscure the ultimate destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://krisoc.ru/uplcv?utm_term=gametophyte+of+marchantia PDF link annotation
    • http://ccsctda.com/ckfinder/userfiles/files/20210908_060333.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/bd71444a6243536983e14c74b1134869/ximukejivigesanutulun.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613837810e137---pekezofo.pdfIn PDF document text
    • http://vinabomi.com/uploads/userfiles/file/92221297292.pdfIn PDF document text
    • http://noithatdangcap.vn/app/webroot/uploads/files/32692012868.pdfIn PDF document text
    • http://mastervgtour.by/var/upload/file/18625834586.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/33238142765.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///dodusodobesapajabizux.pdfIn PDF document text
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89763147083.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/21245450725.pdfIn PDF document text
    • http://kingsfinancialconsulting.com/userfiles/file/xafiporonuxer.pdfIn PDF document text
    • http://erpos.sk/data/files/3900777928.pdfIn PDF document text
    • http://pi-consulting.ch/download/88497412189.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fedf3ac603---95629889678.pdfIn PDF document text
    • https://rezilta.com/psum/admin/userfiles/file/tozedebo.pdfIn PDF document text
    • https://kotata-zlin.cz/obr/clanky/file/25789238435.pdfIn PDF document text
    • http://surestegc.org/documentos/file/nalujefewe.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/21760793545.pdfIn PDF document text
    • http://skkouty.cz/ckfinder/userfiles/files/bapovilagabew.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/l2phc2gtdcf9debe63del6jcs1/56064519143.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/19612633905.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/k2vr86li2fsp0i9o369mtnupat/80825860444.pdfIn 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://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_off0000e0d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EF 10684 bytes
SHA-256: 80a2c4ce142723d0d9a4e868bbacc7231dc0334182a18c229c94bcacebfe90a0
font_02_sfnt_off0001114b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1114B 17836 bytes
SHA-256: 519a6b1e149220740ffa282dab2dead77f88b32016a9ca081d4d17728c59cd17