Malicious PDF — malware analysis report

Static analysis result for SHA-256 822ecd6c0513728b…

MALICIOUS

PDF

82.5 KB Created: 2021-09-01 01:27:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cad35e21309ae7f3716cdef64db401ad SHA-1: d1f89667678f60d657df2358e2ed2c8ec185b1d5 SHA-256: 822ecd6c0513728b06e34aca163341c223232a1c23be2ae07534702790cd69d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The document body is unreadable binary data, suggesting it's not intended for direct user interaction but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://amatnieks.com/pictures/image/3900570273.pdf In PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160707cda6fe4b---lilawakamukujo.pdfIn PDF document text
    • https://activepymes.com/pub/file/karidakaxi.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16070f3716ed13---kugopuveperupijevuxu.pdfIn PDF document text
    • http://cokhibaosang.com/media/ftp/file/biwibalabobefafewuliguto.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/gerivuporuwiwisexafuz.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/71911983692.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/c437e7f4fb1d15cf2436a5ad9d120340/9492742964.pdfIn PDF document text
    • http://jeremypourstarlight.com/clients/5/53/539822683240d2210db56c0084569a8b/File/47589024703.pdfIn PDF document text
    • http://santeh.md/img/files/bojujadajopebolasi.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/70249837837.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/40709744487.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/sukebuzatiponovunebulifa.pdfIn PDF document text
    • http://agrion.org/upload/fichier/jekiluwajuxov.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/jq9vor04ektrr5qmunj2qrg30g/9375484837.pdfIn PDF document text
    • http://hopkinshigh1961.com/clients/878968/File/loremonijavediv.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/89039818525.pdfIn PDF document text
    • http://fanta-life.com/userfiles/file/risurututinusadekagaxatut.pdfIn PDF document text
    • https://cobrawire.com/userfiles/files/71958892827.pdfIn PDF document text
    • http://birzebbugastpetersfc.com/files/file/kakikokisegube.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/badire.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/gesuxi.pdfIn PDF document text
    • https://cargobull.cz/res/file/24103219947.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=kc+to+kpPDF 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_off0000db3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3B 19884 bytes
SHA-256: c06f10b560c193ed78eb9d96e70fda76f782204926a945ef20e1f8042bb40dc7
font_01_sfnt_off00010f7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F7B 9648 bytes
SHA-256: d5d509c069117b4652c1bfc651f9dc5a3bd3c507c4c1021077288a1a8b78c93e
font_02_sfnt_off00012494.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12494 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1