Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b8dd420adaf21da…

MALICIOUS

PDF

83.0 KB Created: 2021-09-23 17:18:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3fc198242f3a82d862d0dfb1d2758b42 SHA-1: ab385e7f101c7fe1d377e050593383c69ba562f7 SHA-256: 9b8dd420adaf21daf8ecfb81759e400944c3e126cddd23cad92084da94e49810
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript and a large number of external URIs. Heuristics indicate it functions as a link farm, with many URLs hosted on potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or SEO poisoning to redirect users to malicious content. The embedded JavaScript is a common technique for obfuscating malicious links or initiating further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7511

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://oniceh.ru/uplcv?utm_term=no+audio+on+android+phone PDF link annotation
    • https://giverny-bkk.com/upload/files/92461085712.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/10981958766.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/55199133782.pdfIn PDF document text
    • http://vip-cond.ru/userfiles/file/wewikotub.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/zapuseza.pdfIn PDF document text
    • https://pasarangroup2.com/contents/files/wufoforobiza.pdfIn PDF document text
    • http://jobsandhi.com/uploaded_files/userfiles/files/fapeporoso.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/35362675628.pdfIn PDF document text
    • http://lica.plovdivweek.com/js/ckfinder/userfiles/files/93013022633.pdfIn PDF document text
    • https://portalkucharski.pl/app/webroot/media/files/nosugemotix.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/18140664533.pdfIn PDF document text
    • http://vanhacollection.com/images/files/balafazebeledudoge.pdfIn PDF document text
    • https://all-new-wow.com/upload/files/sedegufudemi.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/kebazuxedilobidofizalibuk.pdfIn PDF document text
    • https://ocw.tw/uploads/files/53161958046.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/zoraf.pdfIn PDF document text
    • http://cuoredicane.it/userfiles/files/zusazobugekavej.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/787387d72e844b18a224b3868430f51b/72233082541.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/33843356674.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/16007778895.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614b76a2000cd---disuvumonusizeguwupapivil.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/4417ad9ea25556189e1a5650285360a9/96489576710.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/susutekak.pdfIn PDF document text
    • https://salonrewards.ca/images/file/56429987004.pdfIn 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_off0000ebf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF2 10252 bytes
SHA-256: fb10704e6908bf052f3e37148ebf108af088968f465b4185a76554f533071c48
font_01_sfnt_off000102d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ae4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE4 17948 bytes
SHA-256: 6069dbc2aac24e38ebb971be251cb21e93f4f3b35becd2af3db1a7cc9bb7e75f