Malicious PDF — malware analysis report

Static analysis result for SHA-256 d62a8461943f8d0b…

MALICIOUS

PDF

93.2 KB Created: 2021-09-22 15:28:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5965b4b2eab3ee73fe0334780191755b SHA-1: 11ddec6f2c85f6ef5e7fca75b9d9a81fd0a57199 SHA-256: d62a8461943f8d0bc2aa3098da1d13fa6fbd748dc80561f78e42f1594c8f7343
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous external links, with a high-confidence heuristic indicating a link farm on disposable hosting, designed to redirect users to other malicious PDFs. The presence of embedded URLs and the overall structure suggest an attempt to distribute further malware or conduct phishing.

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 http://zenkatsu.dk/files/22582722588.pdf In PDF document text
    • http://tcsklife.com/filespath/files/20210907140323.pdfIn PDF document text
    • http://hibertek.com/image/files/20210913_004722.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/35543282585.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/volojoda.pdfIn PDF document text
    • http://tchid.net/userfiles/file/92688160600.pdfIn PDF document text
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fixujibuxokifokivoxe.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/kilareletifog.pdfIn PDF document text
    • https://promtour-rural.ro/userfiles/file/dunilidujafar.pdfIn PDF document text
    • http://irinabailey.com/upload/files/nifapimufodusa.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/tewekemajofif.pdfIn PDF document text
    • http://omgmediatank.com/userfiles/files/vusobar.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/ea340428bd33890a90a25f8022aa7146/24559528039.pdfIn PDF document text
    • http://snft.ro/media/file/belamuwerobumele.pdfIn PDF document text
    • http://onestep-tokyo.com/userfiles/file/95103464591.pdfIn PDF document text
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/gatezapedokadasamuzoxo.pdfIn PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/siwuwivaxin.pdfIn PDF document text
    • http://klenderbio.com/upload/files/31963019277.pdfIn PDF document text
    • http://internet-trade.cz/UserFiles/file/83498588784.pdfIn PDF document text
    • https://ap-qatar.com/userfiles/files/97551888898.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/54680851378.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/50850624079.pdfIn PDF document text
    • http://geriatriccarenewjersey.com/userfiles/files/kujabilidafivowe.pdfIn PDF document text
    • https://soccerauquebec.com/userfiles/file/goxuxepevikopasegoxujiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=bumble+bee+songPDF 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_off0000ff2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF2F 10292 bytes
SHA-256: 6febd00a154845d64c89ac059db2d7c177e40fa4d5e8fc094d7b6db3091297a2
font_01_sfnt_off00011657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11657 22056 bytes
SHA-256: 23a7a155bd11ab97887b2868d2730dfc2af042584964268a9a5ed78ed5925af9
font_02_sfnt_off00014f58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1