Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bf5fa74b24423a2…

MALICIOUS

PDF

73.3 KB Created: 2021-06-02 06:00:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 9f9f2188e869f878996726e475df55a6 SHA-1: 160dfe9abfd831e531f9640a56acdd3209e71eb1 SHA-256: 4bf5fa74b24423a284a6706dfab8c353fcf7806bc7f6b7005b617ab0cd47cacd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs pointing to compromised websites, many of which are hosted on disposable domains or use link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. The document body, though heavily obfuscated, appears to be a lure related to educational materials, which is a common tactic for phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=problemas+matematicos+para+quinto+y+sexto+grado+de+primaria PDF link annotation
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607b172ec67a4---68672091623.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072c1656d072---51902753720.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/58688153138.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16074477796c33---51971767561.pdfIn PDF document text
    • http://xn--dlek-5qa.com/admin/UserFiles/file/gijumiwobaril.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/xofomotagol.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__60B24A23025AC.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/d04b0124ae8a75b646fd9daedd453269/jipojozavipojife.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/a6832e3c40b43e9deb9fcc03e9889191/tolorunewopo.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/wexuzo.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607181b1654a6---pejezaxovoz.pdfIn PDF document text
    • https://makeswebsites.com/clients/c/c8/c8c605999f3d8352d7bb792cf3fdb25b/File/33241260108.pdfIn PDF document text
    • https://bojovicsirogojno.com//files/fukilif.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/16085eb41af020---jowivosusoruzajosuxez.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e3153a347---41961783618.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/nirowifakogosunogibu.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/86749769572.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d95e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95E 5828 bytes
SHA-256: c020d6a43f23457c2c79dc52ab500074f0dd58a1e412425070e6e56f43c82354
font_01_sfnt_off0000ed18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED18 12624 bytes
SHA-256: ec632afd0faa5ff77c82990a32aea1de07697abd952c174f028635bfc8dcc993