Malicious PDF — malware analysis report

Static analysis result for SHA-256 b84e31fe7a1772d6…

MALICIOUS

PDF

74.4 KB Created: 2021-09-22 10:32:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6c21e6a72eccbd84c52ad3ab829e9839 SHA-1: 33df7678165b88b210c15310fff6f41240739428 SHA-256: b84e31fe7a1772d639a9f2ac77d4d295f14bf67e8d8a0220b149ac5c88d07d6d
126 Risk Score

Malware Insights

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

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous embedded URLs, many pointing to external sites, suggesting a link farm or redirection mechanism. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic specifically highlights the use of disposable hosting for these links, a common tactic in phishing and malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://sarkar.ie/userfiles/file/10114641602.pdf In PDF document text
    • http://mariondhuique-mayer.com/data/file/gilojakuliripak.pdfIn PDF document text
    • https://ferropula.hr/files/78554009660.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/53407106566.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/94081797342.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/79951356636.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/11872328733.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/12855473468.pdfIn PDF document text
    • http://flywings.sk/UserFiles/file/52094505874.pdfIn PDF document text
    • https://fundoohairstyles.com/hairstyler/images/file/kuwazogozaduleliwo.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/44062385406.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/mebidamakumubalenefewal.pdfIn PDF document text
    • http://grapes4u.ca/sites/all/sites/grapes4u.ca/files/42712283950.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/tobatujubedikegovafuguxa.pdfIn PDF document text
    • http://demkapi.com/resimler/files/29826413962.pdfIn PDF document text
    • https://thebottombillion.com/business_school/uploads/file/4801204307.pdfIn PDF document text
    • http://thegoshow.net/userfiles/file/mesipekawepexudosamer.pdfIn PDF document text
    • http://proleague.dk/userfiles/file/verizafusojulil.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161364c046017f---82991982093.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/56184297977.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/70244445503.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/rusetuwibofojogamu.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141c571114e8---xajara.pdfIn PDF document text
    • http://tndgdemo2.com/ckfinder/userfiles/files/57775142341.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/xisefewokivogirilidaliver.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=one+fish+two+fish+pdf+freePDF 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_off0000bfb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7C6 17128 bytes
SHA-256: 5bb875790f366bbe5ff8a9e2cd4188bc9eec1c08b59bd93410502074d761e47a
font_02_sfnt_off000103e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E2 10496 bytes
SHA-256: 0526306f5c4e5cc3b338e7d46f4af586de8c65b503766394c56601496c3ce5b5