Malicious PDF — malware analysis report

Static analysis result for SHA-256 531a18cd1c8288ee…

MALICIOUS

PDF

120.4 KB Created: 2021-06-01 01:42:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 43ae7e185c33149a9c28284d4712749f SHA-1: 90a5d1b7cabe537d38ce7196016916d42936f039 SHA-256: 531a18cd1c8288ee2b479414f48d36d5b69664abc4266a3e0dbe81b9f62f6067
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, but the presence of external URIs and link farm heuristics confirm the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/6j7babcto6lo9lufqgdnh6aac1/93568090210.pdf In PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/7176b44c4df98f95d6b9d1a85771b1a3/69184113361.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3b1dbdcf4---witejogajilu.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/8572a918d582804010145145beeef07a/64762222603.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/51551899680.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/90997408386cb396c52061859f335d32/25759638213.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/67210647295.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/sefen.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/89032323854.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160782314911c2---goxivor.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/147ccb8b1be34156c7bb8200c0460133/fileredujuvakotafipede.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/1c98d8a11d493f1f5ca2fc5e7ef0e784/letoxif.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=keirsey+temperament+sorter+results+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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017950.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17950 5140 bytes
SHA-256: 8fa604d0da2f4b372fb846e08f77db065794ce780132372642ac87f8d91df3a0
font_01_sfnt_off00018ab7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18AB7 11164 bytes
SHA-256: e7f53b97eece780d17265eb3f8a4044923a8620706f054506f29ca40555b79ca
font_02_sfnt_off0001b0ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B0AC 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd
font_03_sfnt_off0001c5d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C5D9 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378