Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca34130e6904c882…

MALICIOUS

PDF

80.1 KB Created: 2021-09-21 20:34:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bc356cb2681cbbe29fc561c4aa1141f6 SHA-1: 31688fa0374d97a8babeb79b25bbd73a59d1553f SHA-256: ca34130e6904c8827d679252a21e6b3f8f09d8e147e1fc83d5836a372b028591
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malware. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics supports the attack pattern of luring users via a deceptive link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://pvesc.vn/uploaded/file/vitelexotonizikavubapese.pdf In PDF document text
    • http://dautuck.com/uploads/userfiles/file/birewevodamukobetobav.pdfIn PDF document text
    • http://cuacuonductudong.com/upload/files/55626380194.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/buvonuvitenonidixo.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/86168320430.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138cfb707f6e---jonexozoxopovasekebim.pdfIn PDF document text
    • http://nemochem.cn/upload/files/godagikigepafuwakobu.pdfIn PDF document text
    • http://drironcat.com/images/file/nujetiporozefajamufugo.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210916180128.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/fukotufewevodelotuvow.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/zubesorulinurokesarimu.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/mifot.pdfIn PDF document text
    • http://northcity.rs/slike/files/50250965957.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/88813869252.pdfIn PDF document text
    • http://dorrstrechy.cz/UserFiles/File/67973113538.pdfIn PDF document text
    • https://pilot-nav.com/ckfinder/userfiles/files/viverelujajivejug.pdfIn PDF document text
    • https://afma.pt/site/upload/file/43967817734.pdfIn PDF document text
    • https://dalilak1.com/userfiles/file/88087309719.pdfIn PDF document text
    • http://sualpturizm.com/userfiles/file/dakovojusuxeletotaremi.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/40837186650.pdfIn PDF document text
    • https://tannhatviet.vn/upload/files/silutimofogukabujixajab.pdfIn PDF document text
    • https://sanruouvang.net/images/uploaded/file/38030622114.pdfIn PDF document text
    • http://abwingstop.com/uploads/files/bugelos.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/kapefajikixane.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+download+movies+from+netflix+to+android+tabletPDF 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_off0000d443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD443 10900 bytes
SHA-256: 4ea6ee3539d5a20cb0045584ce4d79c7f9e17d602b52e8bb838373cf4d62d25d
font_01_sfnt_off0000ed82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED82 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10594 17436 bytes
SHA-256: 304f1d318a4c3333f672cfcd753b5aff6177f2d27612eae4464a29f541642947