Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf8fbf1276eae4f…

MALICIOUS

PDF

94.3 KB Created: 2021-09-13 00:10:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e86af100e91e77e3fccdb467eef04695 SHA-1: 78a61c4f442a6932d541d1c3563ae1db5efb80f9 SHA-256: caf8fbf1276eae4fdae2f8da801cb73ab75df715546532c4cc368232eed0478c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on compromised CMS upload directories or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate a pattern of using these sites to host or redirect to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 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.
  • 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://krisoc.ru/uplcv?utm_term=the+legend+of+korra+all+episodes+free PDF link annotation
    • https://marathonlaval.com/userfiles/files/80771567564.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da8bca4cfb---zonumopatopipikaf.pdfIn PDF document text
    • https://ontogepszerviz.hu/editor_up/67451492909.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0c899b881---nabekaximameko.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c258b79051---tirojomu.pdfIn PDF document text
    • http://eaupureinternational.com/userfiles/file/tisixenisiga.pdfIn PDF document text
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/befakalilofusitesux.pdfIn PDF document text
    • https://pamukoglu.com/userfiles/file/45458134111.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/91064263141.pdfIn PDF document text
    • http://valencia.thepokeluau.com/uploads/files/77325390204.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/kopipazefenarirotazazi.pdfIn PDF document text
    • http://rspon.pl/images/wyswig_images/file/83368417756.pdfIn PDF document text
    • http://konferencii.org/js/ckfinder/userfiles/files/27037218189.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/97156136475.pdfIn PDF document text
    • http://szwygs.com/upload/94165454618.pdfIn PDF document text
    • https://behbehaniprojects.com/uploads/files/bafifusegisixamiv.pdfIn PDF document text
    • http://maraulsan.com/ckfinder/userfiles/files/67359867237.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/86541417449.pdfIn PDF document text
    • https://sskundal.com/userfiles/file/76858333905.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/funopodasixurezubuxatin.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/kujetaroxibuj.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_off00010ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EDE 17084 bytes
SHA-256: 8820081a169373dc2d1b8661757eca1d88fda9212ba4980875e5d30fe9e7f382
font_01_sfnt_off00013b28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B28 10732 bytes
SHA-256: 365b96c9ffab68638c7f0ab731e705bd4d86e4b21482f88eceab2b6c979cd1f4
font_02_sfnt_off00015380.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15380 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1