Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7fd8b6fb31319a0…

MALICIOUS

PDF

78.6 KB Created: 2021-09-11 18:52:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8eb430c5df0ad07a5391967d08e526a8 SHA-1: 7f070c44330a2f0bc95d9cbe9fcd08eac4ec9d5c SHA-256: a7fd8b6fb31319a00a4abe536af839e39eecb09f4fa24fdaaf790841822bf455
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm, potentially leading to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://chamdure.com/DATA/files/lubaribizofemidenafiped.pdf In PDF document text
    • https://korzo-galeria.hu/files/file/74206926949.pdfIn PDF document text
    • https://nwdglobal.com/ckfinder/userfiles/files/saluvikasinuzavetufelep.pdfIn PDF document text
    • http://huntland.hu/upload/file/badurusivesevi.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/vomagexanidasuxetor.pdfIn PDF document text
    • https://sklepbonus.pl/userfiles/file/rasupivawori.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366709d345f---55871807385.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/15273595405.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/89092268091.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090223052320.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/d5f1cd791df078d1f1fa45e0554236e7/vewupi.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393fa7747f1---80226477282.pdfIn PDF document text
    • https://hsse.cl/files/bexusosikap.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109030512013361.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/28785585836.pdfIn PDF document text
    • http://hzaidele.com/images/upload/File/77056242890.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b62c4721f4---dujejum.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/79430936398.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/82185580611.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/43193675927.pdfIn PDF document text
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/49175266219.pdfIn PDF document text
    • http://nhadep30giay.com/uploads/image/files/17467692678.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=valter+despalj+bach+pdfPDF 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://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_off0000cf24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF24 17788 bytes
SHA-256: 98acaec7dff5db491d3d0addfca110e0f7499661a683c8d44be2d936a9ea574e
font_01_sfnt_off0000fcc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC3 10640 bytes
SHA-256: 8616f69c979822ab9805ab427fea670f2dd822bc918c616a54b7663a7627664f
font_02_sfnt_off00011513.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11513 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1