Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5783507781e9ecd…

MALICIOUS

PDF

83.2 KB Created: 2021-09-18 21:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7bccb80b8a6d75efd11e78703f8a25e8 SHA-1: 50fe7cfe88243d1b4254904c741e12b75da77c2c SHA-256: a5783507781e9ecd873f3d514140d44286c323cc4164b51038e5eaa4a59358c2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to potentially compromised or malicious domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags the use of disposable hosting for multiple PDF links, reinforcing the phishing or malware distribution lure. No scripts were extracted, but the overall structure and URL distribution point towards an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://soundspace.eu/Upload/file/55391796739.pdf In PDF document text
    • http://china-zub.ru/userfiles/file/14689968107.pdfIn PDF document text
    • http://papianiarch.it/userfiles/files/73599873342.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/dunupasiwataxa.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/435939308590c4b4a507289e2651eae9/pumipafatafixim.pdfIn PDF document text
    • http://yourbuilding.ru/userfiles/files/1923458068.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/30199798845.pdfIn PDF document text
    • http://keifo.ru/ckfinder/userfiles/files/96855584019.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/wagikumidazuxutunew.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/53033203908.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/55697855118.pdfIn PDF document text
    • http://tecresconsolidamentorestauro.it/fck_data/file/duwirumalirelopem.pdfIn PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-14/20210914055127645153.pdfIn PDF document text
    • https://gmt-tw.com/app/webroot/userfiles/files/ranumixojo.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/22188955671.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/94474944165.pdfIn PDF document text
    • http://universalgroupautos.com/files/others/2243670233.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613023932b120---5287331817.pdfIn PDF document text
    • http://griesvoegwerken.nl/UserFiles/file/14652943518.pdfIn PDF document text
    • http://explosivedevices.ru/media/file/93006987287.pdfIn PDF document text
    • https://viceda.com/userfiles/file/kuzasikugubatasenaxur.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/62508244066.pdfIn PDF document text
    • http://e68momo.com/shopadmin/upload/files/47605919697.pdfIn PDF document text
    • https://epiphanych.com/images/file/42709144269.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=8th+science+textbook+pdfPDF 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_off0000df57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF57 10852 bytes
SHA-256: 254c03a60bb3810a3b300f5926aabd10463c340b6cf9544470521a3b33ee2f08
font_01_sfnt_off0000f827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF827 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11039 18232 bytes
SHA-256: 9b55598d723e6bbf496c0552a3f2c9ebb9e14411c3a2b279b6d5d3fb026b47d8