Malicious PDF — malware analysis report

Static analysis result for SHA-256 bfbb3758187752d1…

MALICIOUS

PDF

79.9 KB Created: 2021-09-20 03:55:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4c7a13409150c6f543e08c02f8546955 SHA-1: 4b161dec4727973586caf53bd122f5d24787b6f5 SHA-256: bfbb3758187752d1c34c6e9518fde11c9f9d766e474ae692717b8010218bd4e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document contains a link farm pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. The embedded URLs, despite some being marked benign, are part of a larger pattern of suspicious link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://uleshuzatabc.hu/files/file/49604183111.pdf In PDF document text
    • https://hsse.hssanesteban.cl/files/tedolatonogo.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/6813e5f3878d9dcf44c9a13abc449583/89375670662.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/4846202901.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/40195214128.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/36236959858.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1631724314.pdfIn PDF document text
    • http://tizianaiberti.it/userfiles/files/51590043940.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130ae90763d6---91215181419.pdfIn PDF document text
    • https://dulsuc.cl/userfiles/file/wezekinulelepatubuwo.pdfIn PDF document text
    • http://secohthailand.com/file_media/file_image/file/bubure.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/badizilujokebivubewuguxa.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/6671315085.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/137650620.pdfIn PDF document text
    • http://oilspecchem.com/files/49718516136.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16147d2899512d---wujokek.pdfIn PDF document text
    • http://citra.cl/userfiles/file/vuzuzojekagexudubaseten.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/83ae7dac38b7da8f5c1dacb8a8d426a3/xeworopev.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/ff35e3ae35b934d404818c4cdd802732/47675175936.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cbb3b64586---68154045580.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/c4884e76ab548da1017503e77d7eb989/kilezadale.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/gilojerafuvofabi.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/10124392641.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=office+365+app+androidPDF 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://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_off0000d41b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41B 10800 bytes
SHA-256: 8b5cde6709ab1ae20a41ceed7bc6c4357e4eb51ec2984251c13d7dd5e9d66a08
font_01_sfnt_off0000ed20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED20 17332 bytes
SHA-256: f77a2ea5ec739dafa4c30e438eb19c75a339772f880f92c69e23618b069a3578
font_02_sfnt_off00011a4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1