Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4bfc7190cb5c814…

MALICIOUS

PDF

72.9 KB Created: 2021-09-26 00:30:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 24c3fbe8e5174c11357bfbd7f97ecba4 SHA-1: 28b97c0192bd784180f5edde4aaba9290658c71b SHA-256: d4bfc7190cb5c814aeaf676fd5f7380d749bc026dff63fc45d14f35dc6c3ae22
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one identified as an algorithmically-generated URL hosted on potentially disposable infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. The presence of numerous links suggests a link farm or redirection mechanism to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drafthe.ru/uplcv?utm_term=dark+theme+for+android+apk PDF link annotation
    • http://cesnek-vysocina.cz/UserFiles/File/41622546255.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///69039546077.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/zatazex.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/90294967719.pdfIn PDF document text
    • https://www.ijmsir.com/ckfinder/userfiles/files/48756714580.pdfIn PDF document text
    • https://tradingphrases.com/userfiles/files/3099604312.pdfIn PDF document text
    • https://homestayhoian.thamtuddt.com/uploads/image/files/83375007374.pdfIn PDF document text
    • http://sushibelovo.ru/files/lanod.pdfIn PDF document text
    • https://interstudy.net/userfiles/file/nakakux.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/lovedawaxamapozokivemefi.pdfIn PDF document text
    • https://granitabrasive.hu/editor_up/mitidavebitazapowepov.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/71206233ceb2468d5ee87d751b795113/dazipugadugiver.pdfIn PDF document text
    • http://kimhoatra.com/upload/fckimagesfile/tokijosezibiwijav.pdfIn PDF document text
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/govoxowaf.pdfIn PDF document text
    • http://vuoncotichdep.com/upload/files/99585185974.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/fumoxegavefarusotogu.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/69290260644.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/68033469430.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/2fae650f6a408e0138ae7575ef5750f3/lazeruwebutopamizasus.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/81411856682.pdfIn PDF document text
    • http://khyljg.com/uploadfiles/files/bobudedexixinuxugoxi.pdfIn PDF document text
    • https://b7b.reviewz.eu/app/webroot/files/userfiles/files/pifisotexu.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/1376997758.pdfIn PDF document text
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/15722224574.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27554606913.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_off0000b7ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7EF 18092 bytes
SHA-256: 6f50841693d12cd77ec4b3826f4a11da3a4b80b9354d9b303ca36fe95d838b6d
font_01_sfnt_off0000e58b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58B 10644 bytes
SHA-256: 6432b442344a238a4adb40910da36adb3a0171450aa3889be81d1761e52c62b9
font_02_sfnt_off0000fdb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1