Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec7b1a7e23c52f3a…

MALICIOUS

PDF

84.5 KB Created: 2021-09-23 22:12:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 79ec1c0ee30b0f7eaa9c0c58a764a03e SHA-1: 912787b468a65e48c373d0cf3521c929ce0a362e SHA-256: ec7b1a7e23c52f3ac781d1840075e657bc5806416b4d000da96de33040b85149
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to other PDF files on distinct, potentially disposable domains, indicating a link farm designed to distribute malicious content or phish users. The presence of external URIs and the nature of the links suggest an attempt to lure users to malicious sites, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://pro-roubenky.cz/UserFiles/File/matibisatavesuwavi.pdf In PDF document text
    • https://used-machinetools.ro/app/webroot/files/userfiles/files/47850882292.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/6943703068.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c36aadc73a---jijunidow.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/juriwubupalel.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/kusorimaxamuwa.pdfIn PDF document text
    • http://granitemountainranch.net/userimages/2724727903.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/48033047864.pdfIn PDF document text
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/winenivigavawuvebu.pdfIn PDF document text
    • http://moonlightmontessori.com/upload/files/jolum.pdfIn PDF document text
    • https://kuraniterbiye.com/resimler/files/12082510837.pdfIn PDF document text
    • http://stl-hk.net/userfiles/72254154736.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/tiberu.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/zukobi.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/xumelonopijifegikotope.pdfIn PDF document text
    • https://stehovani-ostrava.cz/static_pages_files/file/9193919727.pdfIn PDF document text
    • http://stfurnimart.com/file_media/file_image/file/befijakulet.pdfIn PDF document text
    • http://pneusmarene.it/images/file/14551907302.pdfIn PDF document text
    • https://tebra.si/userfiles/file/karurubidoxuwo.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/20219211314302783.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b5ad2d2ab8---89416684343.pdfIn PDF document text
    • http://terrietanaka.com/library/files/duses.pdfIn PDF document text
    • https://podimercrm.com/img/files/zufobujajiguremezuroruga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=c%2B%2B+book+free+downloadPDF 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_off0000e5e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E5 18176 bytes
SHA-256: 99110796a10b2d98ebb6de284122cf6cd625ab0d4e2daada6379c2622f5f8614
font_01_sfnt_off0001155b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155B 10340 bytes
SHA-256: 8a5d5d36fee9d83bb4b503a3041d008dc728732f8bd7a2d5bc83c877dfd21134
font_02_sfnt_off00012ce5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1