Malicious PDF — malware analysis report

Static analysis result for SHA-256 731297b695c13be5…

MALICIOUS

PDF

80.5 KB Created: 2021-09-08 18:52:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c6a35446575ab4c86b9de4f1f99bebb9 SHA-1: 41c5cd54772baf28dd3699cb7de0f4f4619654c7 SHA-256: 731297b695c13be5d0c878d0823dad4f1018d71ad3088ba00c6efe5506484c43
174 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including random URL links and a link farm on disposable hosting, suggesting it's designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature. The presence of a 'download button' lure further indicates an attempt to trick the user into executing a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://sydneystudytour.com/accounting/userfiles/file/10152278078.pdf In PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/39927454175.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/zibemivadalam.pdfIn PDF document text
    • https://12shio3.com/contents/files/tazet.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/77494923472.pdfIn PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/43239840966.pdfIn PDF document text
    • http://alanaf.ru/userfiles/files/61529555374.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/fejidamibinepagipip.pdfIn PDF document text
    • https://cartolmania.it/file/zazulapigimawamidizavived.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/pivumuk.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/30483597590.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/mozixezolimubadebakon.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/6671315085.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/93266939864.pdfIn PDF document text
    • https://bisleriwheel.genefied.co/ckfinder/userfiles/files/ripagajinenaludan.pdfIn PDF document text
    • http://julianina.de/upload/file/futogorafavanikaboboki.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/zetatuwotererukikobiku.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/17776634760.pdfIn PDF document text
    • http://twgo8.com/uploads/base/files/202109061545387427.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/80207054809.pdfIn PDF document text
    • http://dagmare.de/userfiles/file/68763966823.pdfIn PDF document text
    • http://bankerz.in/qpic/files/jixiwi.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/zifonono.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=ronco+food+dehydrator+model+187-04+manualPDF 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_off0000d2a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eab8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAB8 18144 bytes
SHA-256: 17f825444a260665f093a524fb960291890d7878f7a418377f23fbb6dfb1252d
font_02_sfnt_off00011a09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A09 11284 bytes
SHA-256: a868c19b09a7ae868cb3fce797d3f0f6746d5c713cd82aa5a09f1dc9e6a9e97d