Malicious PDF — malware analysis report

Static analysis result for SHA-256 e81c5602a8353033…

MALICIOUS

PDF

78.2 KB Created: 2021-09-04 07:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8af01adcfd11d6a3f4973bce9cb420bc SHA-1: e178e2c4233abe7c620bfed4abc3713b68e2da04 SHA-256: e81c5602a8353033893430c70fabdc161243a761512094fcf03c6b35d51aa2f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to direct users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://color-gateway.com/userfiles/file/21625413599.pdf In PDF document text
    • https://www.retake.dk/ckfinder/userfiles/files/81909811444.pdfIn PDF document text
    • https://biocenfis.es/uploads/assets/file/11072708318.pdfIn PDF document text
    • http://zzquansu.cn/d/files/75761750860.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/vorijakogokubojotumope.pdfIn PDF document text
    • http://ave-france.com/pics/files/salugimo.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160780288af1bb---33896378273.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/sefosomegomovawatosek.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa600a96891---vovatuzijil.pdfIn PDF document text
    • https://ecohort.com/userfiles/files/rizowolapoparikif.pdfIn PDF document text
    • https://epiphanych.com/images/file/85956037610.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/bfacef7fba3dace1203a0cd878aca828/66410078546.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210706_054741.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/sareruga.pdfIn PDF document text
    • http://integrotech.com/zdjecia/file/82688244417.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/555von9vjuk166olq5mgvbuise/xojefivotili.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a46ab9e2aa---39438551681.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/baganonu.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/kizutadalolapip.pdfIn PDF document text
    • http://mountcalvary76.com/clients/9/90/9062e1c9f2360b2cedac6e2854879500/File/89901209135.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/saful.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=rate+of+change+worksheet+with+answersPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cab4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e2c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C6 18272 bytes
SHA-256: 9c1cfc62a64a3a78423c930852587dd285b5982ec3502391690f058f9cb92e41
font_02_sfnt_off000112ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112BA 10792 bytes
SHA-256: 75c11d44dd5db4be4da047bc8234bb66a7e562521442871b9961ad3fca257e05