Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bcf6d91379607d3…

MALICIOUS

PDF

84.1 KB Created: 2021-06-18 19:34:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 813569c1d6b319f53a45fff104b1e85a SHA-1: 26da06cc1000590cc9a83e710f03b8d76f51dba3 SHA-256: 8bcf6d91379607d34239cac516bd27ca7a60062b75764018c4ffef141444bcc3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body's garbled content and metadata suggest it was generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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.
  • 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://www.colours-of.com/wp-content/plugins/super-forms/uploads/php/files/vqhrp2ffe4ca3e1ho4h3uplsk6/76173842227.pdf In PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/1587f45d9abe5d1fcfba767640a5eab3/81325959670.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a52618491---kosetaviwa.pdfIn PDF document text
    • https://planet-for-events.de/userfiles/file/86893117623.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985ea0f1720---puvipa.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/a0df80fed2547f5b28d5ec9442ca800f/93562237561.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d83e1029d---dojeduwavojofutuf.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1607f30d2ba118---96964797523.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/96590570265464ec9280d0e2dba8b2e5/saxiralimawuzorizeje.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/sf2sfdvu4hvb2qh7cird7uvogt/88000955487.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b6c69670467---bediwetoxenobu.pdfIn PDF document text
    • https://unosms.us/userfiles/file/99803899079.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/13187989945.pdfIn PDF document text
    • http://azizolace.cz/images/file/zajenogafivowavaf.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/55d5411ec92286c7ef9123c4409c0682/femopofukumujev.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1608655998c840---51004770481.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=clash+of+clans+base+layout+level+11PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ba9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA9 5132 bytes
SHA-256: 585d32ed1fca7e4fafadced38f9fcf2f0fcebe1a65182c4a793e76447f07d9f7
font_01_sfnt_off00011d36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D36 10968 bytes
SHA-256: 397c7b71264d73f0605770f32ce5b4135831562b0466f7efca772b3b71a8f31b