Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c94da57f0a6d9e1…

MALICIOUS

PDF

70.7 KB Created: 2021-06-19 02:30:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: d3861118a3f56e266181e08ffa25eec2 SHA-1: 85efc977e34c8c70a0773b29cf8ac246f4e125bc SHA-256: 3c94da57f0a6d9e14cfadf9df17dc96a77c3f565de18c1ae5f222cd5c86a4a72
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to numerous distinct hosts, many of which are associated with compromised WordPress installations. The document body, though heavily obfuscated, suggests a lure related to a 'carboxylic acid worksheet'. The primary attack pattern involves using the document as a lure to direct users to external, potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160aeaca8d43dd---96676183883.pdf In PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acc981e3cb3---munutijixuziwu.pdfIn PDF document text
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/dd92fb9ea9824623104dcbeebe51fb76/91063705433.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16097a2c10c643---6325584361.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/powuvifepatetumi.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/o2mlm7v539o380ig036543oel4/xawenotesororawozuti.pdfIn PDF document text
    • http://partnercable.hu/files/14345594741.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e67c4010a---rupaworakesonifojanodozij.pdfIn PDF document text
    • http://christopherdallo.com/file/kezurazosogemov.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/zibadusidofukujezidegebis.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b4dd17538---nimeruvabufokum.pdfIn PDF document text
    • http://moon-villa123.com/CKEdit/upload/files/66576931645.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076c7a9e0af2---81556424899.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/kogimizuvivexonasepige.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a299db2dda3---vulafalu.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/1dba32167741fc4416571f5dd23a18ed/41377500950.pdfIn PDF document text
    • https://psychologgia.pl/Upload/file/junarowekemox.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/DOqCt-cVA4I/uplcv?utm_term=carboxylic+acid+worksheet+with+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD360 5396 bytes
SHA-256: 5db09fefc5782838836f708db3b1356d5948830e4175914f15108ce23877a6a3
font_01_sfnt_off0000e5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C5 12180 bytes
SHA-256: eb6ab93269a9d73a1ab9882d219424261bfaefdc2934cf39db3666301868e498