Malicious PDF — malware analysis report

Static analysis result for SHA-256 91fd41d7acf86a1f…

MALICIOUS

PDF

76.4 KB Created: 2021-06-12 07:41:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: c7f79b39ec91decc4118f915f27aa3fc SHA-1: 6f4452d70eaaa13068573b55c0e6fb01149721ff SHA-256: 91fd41d7acf86a1f09c6c19061db5f94390b5c0c183e428f003ef2058abdb37c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it's designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports its role as a link farm for potentially harmful destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://wastran.ru/uplcv?utm_term=dishonored+all+safes PDF link annotation
    • https://lentes123.com/aym_image/files/39626447790.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160826f4c32a45---51751907835.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d89bcd995f---kimefuferet.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/jejudevimesilixagosub.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16079648d7f7d9---87514216648.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/d0e902e9051e2ecd1b568bbec06bf679/suxelazezep.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606c94394c5ab---dukagevuxapog.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2957c6072f---57745496737.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/5edc60077c75df4460fcede449b1783d/nimetuluzuz.pdfIn PDF document text
    • http://www.onlinetemsilci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160725e6ae8f52---sawezuzininivawi.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a8d5c2b0f---56234236593.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1f64cd238d---12426681089.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/39251752874.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9af357a09---92147645723.pdfIn PDF document text
    • http://alexhofford.com/temp/files/file/21197337252.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/45644438424.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/47002367288.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA5 4992 bytes
SHA-256: 900a914cc287c2cf9cf8dbd46a0495c1923f36911460eeb0b05c57e7898b85bf
font_01_sfnt_off00010098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10098 10756 bytes
SHA-256: c4a47d4ae81819150daa84d62400fc2294bb452e27be8e7381c8fa7c705b16af