Malicious PDF — malware analysis report

Static analysis result for SHA-256 31fb3d5d4d5b278f…

MALICIOUS

PDF

89.5 KB Created: 2021-10-10 22:22:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 57db79431a450b8b13793d8d4259af43 SHA-1: fb2b9cfb4d09c6a1c6ebe7c68277c47a47a1853a SHA-256: 31fb3d5d4d5b278f9c05e620c4a73a975889372822fd26d8e3226e745645358d
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, suggesting a link farm or redirection mechanism. Heuristics indicate it's a link farm on disposable hosting, and ML classifiers and ClamAV strongly flag it as malicious, likely phishing or a trojan. The presence of PDF_URI and EMBEDDED_URL heuristics confirms the redirection attempt, which is a common tactic for delivering malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://huntic.ru/uplcv?utm_term=salmonella+typhi+carrier PDF link annotation
    • https://baoholaodong24.baohohoanglong.com/userfiles/file/sujepemumiwor.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/32215566959.pdfIn PDF document text
    • http://clean-ecology.com/Upload/files/86248170484.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/37974955497.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/xanazikinobasejipeginiku.pdfIn PDF document text
    • http://dotykbylinky.sk/_subory/subory/57268549786.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/15995719026.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/85587940382.pdfIn PDF document text
    • http://www.gulbaharsigorta.com/contentData/file/ralemepofopixepibijaxubik.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/96534704107.pdfIn PDF document text
    • http://motocams.cz/ckfinder/userfiles/files/91543177023.pdfIn PDF document text
    • https://kimcert.com/E/file/mitiwara.pdfIn PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/kakipovofexo.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdfb8acb84---gomeg.pdfIn PDF document text
    • https://oriental-kitchens.com/userfiles/files/93639020793.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/xakesu.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/92820507119.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021091904151752.pdfIn PDF document text
    • http://thanuyentea.com/ckfinder/userfiles/files/getenabuze.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/39728697593.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/votogewekulodagoxipodopu.pdfIn PDF document text
    • http://studiomarcheluzzo.it/userfiles/files/jewulujeru.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/65edcb142b6cb3ceb86051f281ea0da9/xubasif.pdfIn PDF document text
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/jenakefowavamudibuxu.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_off0000f4dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DC 10660 bytes
SHA-256: f84fb2b2f0abd765d9478569eca37865803c56860bb3ab0f6361f38c50efaf67
font_01_sfnt_off00010d11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D11 19996 bytes
SHA-256: b646ecfde432c559467d29bf7ee10f7fc13bb47f5d50b6aeaf70f3243dd54da8
font_02_sfnt_off000140b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1