Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef03a5a05f835ef0…

MALICIOUS

PDF

87.8 KB Created: 2021-09-16 05:09:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bb6d163e28cf67d73fd5296a6dc78afe SHA-1: 57f738d03f1cc61ab8b69a39006afaabce541666 SHA-256: ef03a5a05f835ef07a0cdc3b5b4a27f95ed5f529a26374e07dc6f1900bc792c9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded links, many of which lead to unknown domains and are structured as a link farm, suggesting a phishing or malware distribution attempt. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9746

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://855solution.com/htdocs/cljr/data/files/22352057539.pdf In PDF document text
    • http://sklepjola.pl/userfiles/file/90063021647.pdfIn PDF document text
    • https://manhremhoangvan.com/wp-content/uploads/files/14743469885.pdfIn PDF document text
    • https://kidneystonetreatment.in/userfiles/files/13142695433.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/37777720271.pdfIn PDF document text
    • http://wonderpanel.com/app/webroot/img/file/tixolamu.pdfIn PDF document text
    • http://rem-proekt.com/f/file/30556876948.pdfIn PDF document text
    • https://digireg.cz/upload/pigarufusofojukemuvojug.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/10804226001.pdfIn PDF document text
    • http://nanoscopy.ru/uploads/files/nirijemogitudafadumenaxib.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/fokasukad.pdfIn PDF document text
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/fajomumejaxetejezikenute.pdfIn PDF document text
    • https://gtselect.fr/ckfinder/userfiles/files/pozorasuvazudewugotoxevad.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/fosigogadusagemupava.pdfIn PDF document text
    • http://seosanhrd.com/userfiles/file/22369385890.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613720510b486---23614444820.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/figufatosefawame.pdfIn PDF document text
    • https://kipass.fr/userfiles/file/tubogawazazow.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/12641253234.pdfIn PDF document text
    • http://sintellect.ru/Repository/file/22893410917.pdfIn PDF document text
    • http://cn-noah.com/uploadfile/file/juzulumu.pdfIn PDF document text
    • https://myarchitect.es/ckfinder/userfiles/files/loxizuga.pdfIn PDF document text
    • https://travelone.ae/userfiles/files/88263391638.pdfIn PDF document text
    • http://www.prakashirrigation.com/uploads/fck/files/72028740212.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/20605183367.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/futivupulivebisozed.pdfIn PDF document text
    • http://psn-monolit.ru/img_file/files/57197761271.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=download+stickman+dragon+fight+mod+apkPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d604.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD604 11116 bytes
SHA-256: 28e85fc583d70e7c5105245c0f68c3060a2f2ed2a0d54fb3b564656d5f9781d5
font_01_sfnt_off0000ef99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AB 17700 bytes
SHA-256: 44b8f2b54b161eb8c41b05142a0fa02003b18ec58a2c59f3337aba0a226af1f9
font_03_sfnt_off00013560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13560 17684 bytes
SHA-256: d35e89b3b4c925fd4210c55a73dcf014ea4e5c26742e7939e77236104e210258