Malicious PDF — malware analysis report

Static analysis result for SHA-256 e439bdfb24e1776d…

MALICIOUS

PDF

79.7 KB Created: 2021-09-04 18:18:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 69ee7ec976717953829e7f63672937d9 SHA-1: 64dd5a421ba451e50833bd32ba282bdf2c754db4 SHA-256: e439bdfb24e1776dbca7a3ad1897a72febfeba8819ddff96066e42cbb7c17bc3
176 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URIs that point to compromised WordPress sites and disposable domains, suggesting a link farm designed to lure users to malicious content. The presence of these links indicates an attempt to deliver phishing content or further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://pistant.ru/uplcv?utm_term=mathematical+statistics+with+applications+7th+edition+solutions+free+pdf PDF link annotation
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/20d94b0be5c7a8d65f5a73fa28a23de7/16209867454.pdfIn PDF document text
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/n7hdtedqn5rpv6dg4jba6qcmcv/43223325992.pdfIn PDF document text
    • http://change-sexy.com/files/files/paxefasunit.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1621651032.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/nubuxinejufo.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072137c4d782---15383281265.pdfPDF link annotation
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/b13442d039d554429afaca95f8b30d7b/7190524307.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/bufuduvubovut.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16079daa78e8a8---dozev.pdfIn PDF document text
    • https://tenekedjieva.com/uploads/file/31498552602.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/45015958734.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160c8faf49c7fe---pipaxiliramutejafukagako.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/73451643040.pdfIn PDF document text
    • https://nodka.eu/ckeditor/ckfinder/userfiles/files/povuwutaloliniliwuveduveb.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16082fa29a0765---wokazodibexipip.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/28619927477.pdfIn PDF document text
    • https://rajaunited.com/contents//files/55426593886.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/gefazokilobunisot.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/1c378930098a0b6cab7471045cfe878c/goxuzuje.pdfIn PDF document text
    • http://ruihuitax.com/files/file/vivedotezuguxatijubaguv.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/v08foejhbr66me5gngdvg8p5e0/ralumerotujagogelim.pdfIn PDF document text
    • http://at2apigroup3.com/contents//files/dolonivazimaw.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_off0000cfc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7DF 11112 bytes
SHA-256: 131eeadfc78ff2af947078cc4e9b024cdaa73076c33f6a61025fedce3cb7fd00
font_02_sfnt_off000101b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B5 17896 bytes
SHA-256: 6631a560d9befc1878f72dcfbe7dcb7aa6b1f57701e1de8ae6f9c7feb5dc0a0c