Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ae711ff41fba044…

MALICIOUS

PDF

82.4 KB Created: 2021-09-18 17:48:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b8f6eed74acec64c040d72250aaa81b6 SHA-1: de5cfdd968e0fba3187df42f0b5afe364ad559a0 SHA-256: 9ae711ff41fba044ab4c08ca8ca5bebe64dc5c535dd8c1fcd83a165545720ff8
174 Risk Score

Malware Insights

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

The sample is a PDF document containing embedded JavaScript and numerous external links, many of which point to disposable domains or are algorithmically generated. The heuristic 'PDF_RANDOM_URL_LINK' specifically flags a link to 'http://veterinarioassociatopacinidallatorre.eu/userfiles/files/28991486988.pdf', indicating a likely attempt to redirect the user to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://crysiq.ru/uplcv?utm_term=different+wallpaper+for+each+home+screen+android PDF link annotation
    • https://toyotaautobody.com/ckfinder/userfiles/files/dibisusomobelujeber.pdfIn PDF document text
    • https://bunexim.dascalita.ro/app/webroot/files/userfiles/files/warekad.pdfIn PDF document text
    • http://www.vako.vn/app/webroot/uploads/files/vazenofuwupuludejexuku.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/7389964096.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/bifuxowapov.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/bifumetimuxujami.pdfIn PDF document text
    • https://walkandsmile.com/userfiles/file/38272104597.pdfIn PDF document text
    • https://clickbox.ro/images/file/zusoveziw.pdfIn PDF document text
    • http://sincaremedicaltour.com/js/upload/putamudezu.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210912123506133.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130db3a65193---xuzelufejatuka.pdfIn PDF document text
    • https://autoradiator.mn/uploads/ckfinder/files/ladaronagona.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/pefejijusiladix.pdfIn PDF document text
    • http://zatuchlina.cz/upload/file/sewezoxawaxeporuxewut.pdfIn PDF document text
    • https://jobtiara.com/files/files/93736348165.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-5/20210905235459719963.pdfIn PDF document text
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/vofulusalinet.pdfIn PDF document text
    • http://locthanhroyal.com/upload/files/mavufefejipivukiniri.pdfIn PDF document text
    • https://elemental-ia.com/userfiles/file/55173578594.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/28991486988.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/30590048965.pdfIn PDF document text
    • https://tes-sys.com/uploads/ckfinder/files/20210907/16309473395088.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_off0000dde7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE7 10972 bytes
SHA-256: cac13b49a21280bd5cb0de5bb37637b7d84110e4f8fa290c256a49e8b53d650e
font_01_sfnt_off0000f73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF73D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F4F 16976 bytes
SHA-256: 9fcd38b554056a55cdbac3680d2caa5994a395817a0ab3e75ce4ff9cbc68d0db