Malicious PDF — malware analysis report

Static analysis result for SHA-256 72bb3d2bc057cc4d…

MALICIOUS

PDF

138.6 KB Created: 2021-06-12 21:48:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 67eda31bd79aa755d834e88f3b827299 SHA-1: 6f566992939a434a21c71b44e3411fc2fbfc655c SHA-256: 72bb3d2bc057cc4d025e014d6f1b2417301fa899f1e19c74b65d6f9d340cf0f0
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The primary URL, 'https://smidgel.ru/uplcv?utm_term=9th+class+chemistry+book+pdf', is presented as a search result for a chemistry book, indicating a social engineering pretext. The ML classifier and ClamAV detection strongly support its malicious nature, likely for distributing further malware or conducting phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://smidgel.ru/uplcv?utm_term=9th+class+chemistry+book+pdf PDF link annotation
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160afa5c7f3f55---pusutiniv.pdfIn PDF document text
    • https://t2sc.me/userfiles/towovekisiwe.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/xotifudusoje.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8f82d1121---36568815703.pdfIn PDF document text
    • https://llsindia.in/FCKeditor/file/26259581387.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d52d7d346---73287268839.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607611ff97d7c---79769063320.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae72ba85064---37552136683.pdfIn PDF document text
    • https://castel.ro/userfiles/file/96375254767.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081eb9529291---59783390622.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/zazobok.pdfIn PDF document text
    • https://vannordenvastgoed.nl/userfiles/file/wetezabofurinizuvodivodej.pdfIn PDF document text
    • http://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/f43bc7c855688dae36f4dc4da6457dfe/1149740207.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/d89a3e5a8ca828634aaa3380f6b89df4/lorodivokexuwafovifoxewag.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea57e74933---nofinejowogopupewik.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/00a8ttibv9tb6na7iliknnjfa6/nateme.pdfIn PDF document text
    • https://coevent.ru/upload/files/19253139324.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/d698c3220cd4626c7ed9ae467bcc5602/72811044236.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001d712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D712 5444 bytes
SHA-256: f965189d9a7b559513d9dea0325bed99444e918898d84d7de8e4318b86673b2e
font_01_sfnt_off0001e98f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E98F 11124 bytes
SHA-256: 276ff0ae797c5a33ae1acf303c0d49e272285da8504129f7092ed86a6215eb38
font_02_sfnt_off00020f02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20F02 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378