Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a97373b2e182ef2…

MALICIOUS

PDF

88.4 KB Created: 2021-09-14 07:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 618b2f312d229ac6f812a49f75f5817e SHA-1: f1a0e5be4eec3fcc7791910909ed4c27479dd384 SHA-256: 4a97373b2e182ef2ee34621266c5dac2287bbe2ff262fff3a4e4b384e4f43243
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to multiple external URLs hosted on compromised WordPress sites and disposable domains. These links are likely intended to redirect the user to a malicious payload or phishing page, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://393citizen.com/upload/files/89235445694.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16137f690cf7da---voruvetole.pdf
    • https://ambulatorioveterinariosismondi.eu/file/xosogonuxijofipofij.pdf
    • http://aryajob.com/user_upload/file/fubowadagolilifavabeni.pdf
    • http://beijingteye.com/upload/files/bexujoretizifufefejinod.pdf
    • http://problemconsulting.com/img/download/files/dagidigomu.pdf
    • http://electriccityusa.com/images/fck_uploads/file/xapafefogenogibaz.pdf
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/f030d50d978f206923b3ed0ff3816d83/79526683173.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132394627597---90764284057.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c6094f562---4840497288.pdf
    • https://nangluongvada.com/uploads/files/96386265923.pdf
    • http://enotecagaribaldi.it/userfiles/files/duziporos.pdf
    • http://jeyadhurgatemple.com/userfiles/file/xemar.pdf
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/muxex.pdf
    • http://immopolignano.lu/images/sekilugopokuzevo.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/161337f213eb63---94625899718.pdf
    • https://mi-stores.com/basketballtotaal/images/editor/file/13240267728.pdf
    • http://wernitznigg.at/files/98802752823.pdf
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/movokafevatimu.pdf
    • http://88cpap.com/userfiles/files/83177632394.pdf
    • https://stiglic.sk/userfiles/file/40610620599.pdf
    • http://aliceinformaticasrl.com/user/pages/50742059802.pdf
    • https://vico-real-estate.com/ckfinder/userfiles/files/verenakidowizubizo.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1613637d2cf9e5---wuronexozinipafijenobob.pdf
    • https://hilanguage-com-tw.triangle-design.com/files/fikofixujuwodogopirezux.pdf
    • https://iphone-odklep.si/vsebina/26959717082.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=5e+creating+a+character
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f588.bin
02e067aae1e8fabb1dad7ab6164f4b7acf715cbe74c56a5a01c4f3ece69e3c1f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF588 10212 bytes
font_01_sfnt_off00010c5d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5D 16792 bytes
font_02_sfnt_off0001246f.bin
817d79167a56960177b15cb0d5b15c0d14870effb26152468f932f74b6a6d8af
pdf-font-stream PDF embedded font (sfnt) at offset 0x1246F 18388 bytes