Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb8df4826d8ef8a4…

MALICIOUS

PDF

80.8 KB Created: 2021-10-14 09:17:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: eb4d7eddd1777aa341a2075b6c33e8e6 SHA-1: 633edeee2ebf76f4147e8a03836c9bcfdc3ad7bb SHA-256: cb8df4826d8ef8a43f2917eafc48f41ac24ec63216978ad4e7562ae432f9fd27
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true malicious destination. No scripts were extracted, but the overall structure and heuristic firings strongly indicate a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://laborke.ru/uplcv?utm_term=inductive+bible+study+marking+guide PDF link annotation
    • http://esistore.com/userfiles/file/358902752.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210918_623F08206F5D092E.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///wuwenof.pdfIn PDF document text
    • http://rollfactorytogo.com/uploads/files/dilegusapod.pdfIn PDF document text
    • http://improntediteatro.it/userfiles/files/49820922569.pdfIn PDF document text
    • http://zajazd-broadway.pl/galeria/file/demufedo.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/junosop.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/pezusavugutoreto.pdfIn PDF document text
    • http://bagliodeimille.it/userfiles/files/70138565040.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/92568311253.pdfIn PDF document text
    • http://comlark.ru/userfiles/files/mowexogutig.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/pogikumozetunapudidipadiz.pdfIn PDF document text
    • http://lukinserv.hu/file/94678030255.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/84782270043.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/gokeduvokirodanamutuv.pdfIn PDF document text
    • http://ustunongel.com/image/files/zilezeranizepene.pdfIn PDF document text
    • https://stoneappeal.in/FCKeditor/file/xedubikivaxesogabapuduf.pdfIn PDF document text
    • http://xn----7sbjvweekof5d.xn--p1ai/files/files/lifopan.pdfIn PDF document text
    • http://puisan.ru/uploads/file/88641582771.pdfIn PDF document text
    • http://kovospm.cz/fotky/file/fotuwuranuginigemof.pdfIn PDF document text
    • http://reafamily.lt/ckfinder/userfiles/files/24194324557.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/6c9920fb1774a6e05c0f71207a12631a/92522974667.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/4274049454.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_off0000d19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD19E 11056 bytes
SHA-256: a74f0bbf46265d95d0a724c83ccac2ab846bf9e7467ed5d6241cb7851bdcbeb8
font_01_sfnt_off0000eb33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB33 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10345 19652 bytes
SHA-256: ccda900d2618fdb799fd1cf132bf9f30d3b1393a737989aab0e810a52468c15d