Malicious PDF — malware analysis report

Static analysis result for SHA-256 058876192408b74a…

MALICIOUS

PDF

70.8 KB Created: 2021-09-17 13:29:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8bd25d8c116e07698e85b64f9edd76a5 SHA-1: b2dbebe94dcfcc5b798a9324eaf1d7d74cc62de7 SHA-256: 058876192408b74a31e1cb91ef4eb845a1d512983aaead00138ca888f53b7c81
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm pointing to compromised WordPress uploads and disposable hosting. The embedded URLs suggest an attempt to redirect users to potentially malicious content, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure and URL patterns are indicative of a common malicious document delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=fluid+mechanics+bansal+book+pdf PDF link annotation
    • http://kledingindex.nl/images/uploads/zufuxejojeriro.pdfIn PDF document text
    • http://d2dgroup.net/upload/files/5412887860.pdfIn PDF document text
    • http://onlinemidias.com/ckfinder/userfiles/files/45854633565.pdfIn PDF document text
    • http://chinahongji.com/d/files/83707405265.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/70149833228.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/73911586499.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/b81bc6691d807f64e788731dbaaf6fb4/vasimevujitewev.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130488e77393---tosimot.pdfIn PDF document text
    • http://hoaphathotel.com/luutru/files/88070397150.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/difereberamabadu.pdfIn PDF document text
    • http://electronicaindex.nl/images/uploads/78513884274.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/xamas.pdfIn PDF document text
    • https://bitree.com/ckfinder/userfiles/files/waxonisuvorep.pdfIn PDF document text
    • http://year-c.com/upload_fck/file/2021-9-14/20210914183305444020.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/duwuzavowagafifod.pdfIn PDF document text
    • http://studiocastigli.eu/userfiles/files/30836440230.pdfIn PDF document text
    • http://siblom.ru/files/upload/file/zoramatodebemusim.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c36a3c5876---winolefu.pdfIn PDF document text
    • http://dreamcatcherltd.com/userfiles/file/56518144723.pdfIn PDF document text
    • http://budka39.ru/files/xadabogabafofaxifox.pdfIn PDF document text
    • http://mehmetrasimmutlu.com/icerik/file/53956678607.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_off0000b31b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31B 16316 bytes
SHA-256: 301ba307aa95d71c32817cade17be67cf4f4302fe1cc0cc4282b712a33e28be7
font_01_sfnt_off0000dcec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEC 10996 bytes
SHA-256: bcda944595784834e28419ce12f94f9dd5a154273115b68a399e2ed0ffbab2a8
font_02_sfnt_off0000f5f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1