Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6b2bb89500785aa…

MALICIOUS

PDF

81.6 KB Created: 2021-10-09 23:04:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b341f09c54b6e6ea37ced05aa8cae6e2 SHA-1: 1d721b1a82de1b2e0ebcf0bba55a384b9b0bc090 SHA-256: e6b2bb89500785aaf194708d0f6979433c1d6cd7b1f308b6c772179aa7bacbb4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are embedded within the PDF structure, suggesting a phishing or link-farming attack. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is part of a network of disposable hosting sites designed to lure users. No scripts were extracted, but the primary attack vector appears to be redirecting users to malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://infrive.ru/uplcv?utm_term=elements+and+barriers+of+communication PDF link annotation
    • https://cuichi177.com/uploads/files/202109121252362391.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/loruxigakebexot.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/1ebfc35bbe68cd5b736fbb3d1aa1a7aa/85614410472.pdfIn PDF document text
    • http://cdkuysuujk.handysociality.com/upload/files/mijovato.pdfIn PDF document text
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/30702894969.pdfIn PDF document text
    • http://uforoi.com/app/webroot/uploads/files/balazedaxi.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/garubujegiriwitoxoveja.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158e9ce0fddc---dorenazaxurutuxuvap.pdfIn PDF document text
    • https://evrenmentese.com/upload/ckfinder/files/30132225428.pdfIn PDF document text
    • https://florerialafloresta.com/ckfinder/userfiles/files/wuworetivol.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/96833104548.pdfIn PDF document text
    • http://fullx.net/files/60356786022.pdfIn PDF document text
    • https://incoyun.com/calisma2/files/uploads/jutawuzobanufajukexemakar.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/39055740191.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/liviwavejukesor.pdfIn PDF document text
    • https://fa-vietnam.com/webroot/img/files/dakurawuzodojuwere.pdfIn PDF document text
    • http://skontrolsengineering.com/file_media/file_image/file/xixekari.pdfIn PDF document text
    • https://exam10.menapoint.com/app/webroot/upload/files/wutukutuviropuwux.pdfIn PDF document text
    • https://langumeistras.lt/i/File/wevusagodawarawowoxawu.pdfIn PDF document text
    • http://julianowka.pl/ckfinder/userfiles/files/kisopemomasozijemobinuxir.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/30599550444.pdfIn PDF document text
    • https://swiz.eu/files/editor/lopujazuz.pdfIn PDF document text
    • http://sbkf.org/files/files/21888372023.pdfIn PDF document text
    • http://dubiliergarten.de/uploads/files/libipab.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_off0000d7eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7EB 18844 bytes
SHA-256: 8ca1a52d2800d65c266775d8128a2127fe45ebf55c8b7360eaca1645da0effc4
font_01_sfnt_off000107bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD6 10860 bytes
SHA-256: ade9555625e17c85f7cb9b8c8bcc0f4b19adb5a4e4f77d6a7c5ae6a84898aac8