Malicious PDF — malware analysis report

Static analysis result for SHA-256 b996229f7a005d89…

MALICIOUS

PDF

77.4 KB Created: 2021-08-17 16:29:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: 5edc8b03c429dec7bc694582e17249a1 SHA-1: 9fbf19a7c8ffbd59fcad5dba1739cdb02c76bab6 SHA-256: b996229f7a005d8938bf50b796a42f31922deb0b222a47de1e402cb3e6fd8988
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. It contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of 'utm_term' parameters in some URLs indicates an attempt to track user engagement with these lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://huntic.ru/uplcv?utm_term=cuadernillo+de+matem%C3%A1ticas+para+tercer+grado+de+secundaria+con+respuestas PDF link annotation
    • http://ttlh.vn/storage/ckfinder/files/25130564858.pdfIn PDF document text
    • https://premium-house.uz/images/file/lixokakaz.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/1k36eeado2s96157jjra5jtp3f/rosixutulisiwuzamu.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/dagip.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16113e5c57f62c---99272621992.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/f1b68df44162f546f74de5141b2e7d00/dawowabelijuxewigajilod.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16086469f9a23a---40993683974.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087ed548400d---70040925013.pdfIn PDF document text
    • http://hitoduma-d.com/files/files/gujixuwanekela.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/b26053b1155093e9ebaf51a57b8d24ca/nobufobi.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ad030351e15---bokiguges.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/timorulojamoxowupenulu.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/92c008a542b3c5f6edb9d508430c2afc/pesezixisamogetiligivij.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/sjg8uf98pigpr0e9k2dfmjq20e/69585926376.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/24183074001.pdfIn PDF document text
    • https://attack.lt/images/files/jupajapes.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/raxorotijurufinumofel.pdfIn PDF document text
    • http://daonshop.com/files/fckeditor/file/lezetosanu.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/effc211e1e16a75d9d4b4f6797e06088/modesilakazuveduwisopo.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/59906899694.pdfIn PDF document text
    • http://mientrungland.net/uploads/image/files/62807352870.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/gitopogegefif.pdfIn PDF document text
    • http://whscardinals1963.com/clients/9/9e/9e5fab02d16e7113a74bdd4e7828f974/File/27005709673.pdfIn PDF document text
    • http://erpos.sk/data/files/95638248635.pdfIn PDF document text
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/61428884526.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_off0000c516.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC516 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2D 11168 bytes
SHA-256: 332eee95620d1223d1d7b0c2a43890bf0b12370f53c106db777cf31506660325
font_02_sfnt_off0000f6a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A2 17732 bytes
SHA-256: 0fdb12512ae9e29679c14ada7590a5a9d5476511b2b90769a83ccbd718027e4b