Malicious PDF — malware analysis report

Static analysis result for SHA-256 687368b9ede7f7b3…

MALICIOUS

PDF

86.1 KB Created: 2021-09-17 13:46:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fe398c93177d4cd99389f7f205e6c381 SHA-1: a4d8ff7905a0c9295962c5378d45a98f7da8ad9e SHA-256: 687368b9ede7f7b37ec862b7a51599ca127bf0249f9ec94d6c42f6018ed2b0a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised WordPress installations, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://krisoc.ru/uplcv?utm_term=manga+free+download+pdf PDF link annotation
    • http://opgzvh.hr/upload/file/gixekajorepa.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/valetokamowiveli.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/6c3850b0ea46739872efdd2caedf9907/jetora.pdfIn PDF document text
    • http://annamsaigonlaw.com/upload/files/94870064855.pdfIn PDF document text
    • http://alacarte-husum.de/userfiles/file/3423279760.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/79160360179.pdfIn PDF document text
    • https://bititechnika.com/uploads/file/zajazagarul.pdfIn PDF document text
    • http://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/95961628938.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210914123204190.pdfIn PDF document text
    • https://hinodanang.com/uploads/image/files/rugumorosamuj.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136f54d5106d---wujuxidos.pdfIn PDF document text
    • http://adwokaci-pila.pl/userfiles/file/49850713574.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/muzupukejupanukomig.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/59039393749.pdfIn PDF document text
    • http://metisentry.net/ckfinder/userfiles/files/matepa.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/sijejakarupakujida.pdfIn PDF document text
    • http://hotelamadeustorino.com/userfiles/files/60092494594.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/takefomawi.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/57152204639.pdfIn PDF document text
    • http://theheavent.com/userfiles/files/jazilinujawujemeg.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/63192740978.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1613667ff120b1---17841880504.pdfIn PDF document text
    • http://irodori.kir.jp/files/file/tesowinufibudunan.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_off0000ee47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10659 17512 bytes
SHA-256: c0fee57773f806e77d45942c694f711d2a382a9b86df0f33f6f0d95fdbfa516b
font_02_sfnt_off00013360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13360 10396 bytes
SHA-256: ba708a919a28ef5b2ca1b39b16e6272f6ed44c86aa3881a1fcaea0c1d7eefd14