Malicious PDF — malware analysis report

Static analysis result for SHA-256 bfbd79e901515a86…

MALICIOUS

PDF

77.9 KB Created: 2021-09-09 00:47:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d0f6d107a5a735ba5da5e20a4852e019 SHA-1: 5b472520fe131061aba5e2b402cb3109632981c2 SHA-256: bfbd79e901515a8641c65852a767fa99aa019fea8086b350a0f45e98038e7e83
126 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 embedded URLs, many of which point to suspicious PDF files on various domains, suggesting a link farm or redirection mechanism. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports the idea that this PDF is part of a scheme to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://anhuishangbiao.com/upload_fck/file/2021-9-4/20210904124535785164.pdf In PDF document text
    • https://marathonroller.com/userfiles/files/pobaxawazubezafokuvute.pdfIn PDF document text
    • http://thomasgearon.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kibalivitufadameboreg.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/2237067824.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161373f08cef39---mijopu.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/34b9d851668e2b350177b21066f8aafa/43445754224.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/ravomatijosifaza.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/kuwejerofigafuwodewuvu.pdfIn PDF document text
    • http://facyt.com.ar/ckfinder/userfiles/files/78471183140.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210908224923_YnVzb3Rpbmlsb3dva2lrYXZpbg==.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/83746221795.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/97996891140.pdfIn PDF document text
    • http://kozelsk-adm.ru/files/uploads/files/11435395911.pdfIn PDF document text
    • http://tornyanggrace.com/upload/file/57472099563.pdfIn PDF document text
    • https://durimawar.com/contents/files/nejilom.pdfIn PDF document text
    • http://targhevaticane.it/userfiles/files/95406355694.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/60511431157.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/71412354361.pdfIn PDF document text
    • http://rassadaspb.com/new/files/file/49629221532.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210906_7B378A9CE053E30B.pdfIn PDF document text
    • http://vibrobreaker.com/files/files/xituridobuwarabuvumusaxil.pdfIn PDF document text
    • https://n-v-v.dk/userfiles/file/gulapiwevupe.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161392d5eec103---jajab.pdfIn PDF document text
    • https://szemvidito.hu/sfwkr/feltoltesek/Images/Image/89149492103.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=java+ide+for+androidPDF 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_off0000cd26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE538 17832 bytes
SHA-256: 9a876c072cf9b42e986c975150a6e648db7af1ca6e352fe7c2ec6788ae292445
font_02_sfnt_off0001137d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1137D 10092 bytes
SHA-256: f1a19aa93973047f5a6479802b4b04ded643bf0c93ea25313195a18096f7554a