Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d9a687b5470ecb…

MALICIOUS

PDF

72.0 KB Created: 2021-09-26 19:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 46ead241bfa51447fbfbbc01d82aa586 SHA-1: 252ebde32b0c9f9211579cdc731fb2cc7e71aeb5 SHA-256: 81d9a687b5470ecb0d37c92b57268d11f30eb40ecd80dfd536bb59f29c265ea1
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one specifically identified as a random URL likely leading to a malicious payload. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is part of a link farm hosted on disposable domains, further suggesting malicious intent. The ML classifier and ClamAV detection strongly indicate this PDF is malicious, likely used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://nomylo.ru/uplcv?utm_term=how+to+see+who+viewed+my+igtv+video PDF link annotation
    • http://dworbieland.pl/userfiles/file/74783628894.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/55258523699.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/72319892285.pdfIn PDF document text
    • https://rezilta.com/psum/admin/userfiles/file/dujixapadimiluvitopibox.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16145861e8256a---45038235368.pdfIn PDF document text
    • https://vespaclubcagliari.com/userfiles/file/3433527097.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/a73ef7749f04a2974c22ead2cecfa908.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/26655315774.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/mipevutalixetunov.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/konigufubaxiwagudasewa.pdfIn PDF document text
    • https://matagujrischool.com/admin/imagetemp1/file/texudubemimurujolenebake.pdfIn PDF document text
    • http://benrassam.com/uploads/files/luvipu.pdfIn PDF document text
    • http://identik.hu/editor_up/84121209243.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210909200251.pdfIn PDF document text
    • https://ip-pharma.net/data/files/3473722939.pdfIn PDF document text
    • http://hagelkonzept.com/userfiles/file/xapefuk.pdfIn PDF document text
    • https://anhhuynoithat.com/asset/files/doxizodosumidalikufepi.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613678de76627---66633844959.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/1141836816.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/xijebojugidagoned.pdfIn PDF document text
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bebewutudogiwupariwixu.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/62449922139.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_off0000b1ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1CA 19348 bytes
SHA-256: e283a4b2072cccb59fd7f18b66150771c04d2c62bc2b0ecdf130cb7886855d10
font_01_sfnt_off0000e2a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A6 10540 bytes
SHA-256: 012e541c829acd1801824a57754f5c006734bbab294daaff83aef20c94e8ae89
font_02_sfnt_off0000fa84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1