Malicious PDF — malware analysis report

Static analysis result for SHA-256 4099685c1469535f…

MALICIOUS

PDF

79.8 KB Created: 2021-09-14 19:24:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 123d4e5d07701b31bddcbaba1ad70aa7 SHA-1: 22e65687caa520e37a3c14a299d62c78dfd18be5 SHA-256: 4099685c1469535f55bbd464c59fb91ac234a32dfdf0e423fcbe5c308dff2be8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to external sites, suggesting it functions as a downloader or redirector. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://thayloilocnuoctaihanoi.net/upload/files/busafunixiboveres.pdf In PDF document text
    • http://www.nachtruhe.info/up/files/gasovolowaxejikapigidudot.pdfIn PDF document text
    • https://beldapromosyon.com/calisma2/files/uploads/88408909196.pdfIn PDF document text
    • http://viajaconsciente.com/imagenes/userfiles/file/dovixezadowerezekowiso.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/85497379734.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/wozepab.pdfIn PDF document text
    • http://triple-a.co.th/ckfinder/userfiles/files/38161878355.pdfIn PDF document text
    • https://altaamir.ipixpms.com/Rapport/public/assets/ckfinder/userfiles/files/likimek.pdfIn PDF document text
    • http://hoilhpnqbthanh.com/upload/file/dagutenasezavipevetixa.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/lajadafadufomaze.pdfIn PDF document text
    • https://lose-weight.tw/upload/files/fotujozasiniwudoki.pdfIn PDF document text
    • http://eltprof.ru/userfiles/file/2621796961.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/libenawaxazirutakubopa.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/202191949426174.pdfIn PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/87447339872.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/14194243471.pdfIn PDF document text
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/33425290558.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/kutimibasixajadozalaj.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380a5791a4f---birikivulivuvovolupetijul.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/bamimap.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/dapanap.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9474b3405---furosesozud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=descriptive+k+wordsPDF 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_off0000d668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD668 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE7F 10440 bytes
SHA-256: 5cc03cf94c4b0cc8d29f6178363314c9de250c72ad59cfcc9f1a213bba0c1fa8
font_02_sfnt_off00010661.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10661 17108 bytes
SHA-256: 4bea5c7f2cc04d3dc355fecba9942006ab4fea52ee9e2c3fcde099a553dac4be