Malicious PDF — malware analysis report

Static analysis result for SHA-256 53f7d5b3f043444e…

MALICIOUS

PDF

80.1 KB Created: 2021-09-12 19:51:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c5a407d224fdcf2ba1fa098d5e38f833 SHA-1: 87e50f260966fefd93a129e598a41095dae20d54 SHA-256: 53f7d5b3f043444e4d5854839c3c0c196a9af0c2231e16f12bc02199cc369e2c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous external URIs, many pointing to potentially disposable domains, suggests a link farm or phishing campaign. The heuristic 'SE_URGENCY_LURE' indicates the document likely uses time-sensitive language to prompt user interaction, a common tactic in phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/tukezonok.pdf In PDF document text
    • http://alituncer.com/userfiles/file/nefipob.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/bazunojafifadep.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/xoxirefol.pdfIn PDF document text
    • http://suliaox.com/v15/Upload/file/2021912459556743.pdfIn PDF document text
    • https://aayams.com/userfiles/file/jozurivinuko.pdfIn PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/30359431751.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613524204c537---bepijetexisepunanidijozo.pdfIn PDF document text
    • http://suaups.net/userfiles/file/dizaxisulajabuzubigam.pdfIn PDF document text
    • http://brava-ekb.ru/userfiles/file/nejupusemevaxem.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/fimawefa.pdfIn PDF document text
    • https://twinslock.com/locktactyuma/userfiles/file/mosizemoxevovugudero.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/96141180107.pdfIn PDF document text
    • http://exdebt.bg/userfiles/file/bobelixisejolokugepufeg.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/3051269239.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/3751622614.pdfIn PDF document text
    • https://abriganature.centralcms.cloud/galeria/files/2721946288.pdfIn PDF document text
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/75760691345.pdfIn PDF document text
    • https://robodom.si/files_vsebine/kifaroduriwuve.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/97584608834.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/zopurafe.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/93876218322.pdfIn PDF document text
    • https://visualarchive.bg/files/22433195013.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=de+cbz+a+pdfPDF 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_off0000d677.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD677 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8E 10084 bytes
SHA-256: be9fc8edbcde62a1c426934ca8d0aec9ebdbdf60c2ccd2f855f4b2f3636d33ba
font_02_sfnt_off000104f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F3 17864 bytes
SHA-256: a4db0a181c3e35054bdc92381694df2d047835bca7520310faaf98ece84ef640