Malicious PDF — malware analysis report

Static analysis result for SHA-256 837580c9b7389ece…

MALICIOUS

PDF

72.1 KB Created: 2021-09-27 01:56:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e3130960f9586848d1ef88fa12073626 SHA-1: c8227c4eb38ba4207c1c9260edebd4f804abb7b2 SHA-256: 837580c9b7389ece2841d8bcc21edb7a94673c9dddf8186fcc96597e82b14132
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of these links and the PDF structure strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=township+playrix+game+download PDF link annotation
    • http://kyanite.tv/userfiles/file/virapijipujoxexaz.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/xufezizewiroponi.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202109122317517419.pdfIn PDF document text
    • https://successalpha.team/upload/files/91086121078.pdfIn PDF document text
    • http://ginzaoakland.com/uploads/files/20193449566.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/nonirigewavotezipaxop.pdfIn PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/solifenufeja.pdfIn PDF document text
    • http://scouttautomotive.com/editor_uploads/system/files/fikebixuvax.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/0f8d8932cd8c5c1c9dffabd784d4efee/tiravemugibeja.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/fukarofoxuzosusanidefima.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/161406fb60dfe8---68567799680.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/85475563511.pdfIn PDF document text
    • https://totalsewa.com/userfiles/file/dajibolamoto.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/14096776919.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/lufarosapotezapasuvulun.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613813eed155e---fugurakosodupadomobes.pdfIn PDF document text
    • https://totspotdaynursery.co.uk/ckfinder/userfiles/files/92123452666.pdfIn PDF document text
    • http://fotofolliasanlazzaro.it/userfiles/files/vokirudijogul.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/misem.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109181536481830.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/50544068467.pdfIn PDF document text
    • https://dacola.com/upload/files/87496067503.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/daratiwej.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_off0000b15b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB15B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c972.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC972 11004 bytes
SHA-256: 3fe22a8ef3d9934bc9da25ad3e5fa54f836fb05db34235c84c38edd3a9137579
font_02_sfnt_off0000e2b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B5 18108 bytes
SHA-256: 6318249ed36924c178dac6d2a2cb97a114798bcdb5dfb78eb79548e74f8dc20b