Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b04fe413f3f766…

MALICIOUS

PDF

81.3 KB Created: 2021-09-15 21:58:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c558068a6238a062eeb0c715780730b5 SHA-1: cef66d4b365df2c2fbfd5e5349a511987f63f798 SHA-256: 87b04fe413f3f766299cff17ae5bab192d71e28b33b93ff40c49f0a48810e0f7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to disposable hosting, indicating a link farm designed to redirect users. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies this pattern. While no scripts were extracted, the presence of many external URIs suggests the primary attack vector is directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cructi.ru/uplcv?utm_term=how+to+recover+pictures+from+broken+phone PDF link annotation
    • https://coop-alternatives.fr/images/images/56325987180.pdfIn PDF document text
    • http://www.gulbaharsigorta.com/contentData/file/87529678917.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161402a503aea9---buzewedosabudekatukuru.pdfIn PDF document text
    • https://miltonmattox.com/userfiles/file/15792946917.pdfIn PDF document text
    • http://tsyrulnikov.ru/upload/file/52772330882.pdfIn PDF document text
    • http://canyonmeadows.org/userimages/fizisorasi.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/27621644154.pdfIn PDF document text
    • http://355353.ru/userfiles/file/getufonuzemilakisa.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/sokanilorevigusimag.pdfIn PDF document text
    • https://centrumschoolka.pl/photos/file/kegetumagawefidas.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/20335321277.pdfIn PDF document text
    • http://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/70873360385.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/11159132794.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/5051274675.pdfIn PDF document text
    • https://comfort8889.com/upload/files/mutoligepakogosunevun.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/rajavawenirorajobibixesu.pdfIn PDF document text
    • http://harposwebdesign.nl/app/webroot/files/userfiles/files/mewap.pdfIn PDF document text
    • https://domilot.com/uploader/files/dagajape.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/46683277247.pdfIn PDF document text
    • http://st03.it/userfiles/files/38579297214.pdfIn PDF document text
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30117657032.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/sabofi.pdfIn PDF document text
    • http://china-spec.ru/userfiles/file/valegijiw.pdfIn PDF document text
    • https://www.kuwaitpolyurethane.com/ckfinder/userfiles/files/suxitajaxesoli.pdfIn PDF document text
    • http://www.vako.vn/app/webroot/uploads/files/ziropowuwifezejanixe.pdfIn PDF document text
    • https://araprinter.com/ckfinder/userfiles/files/fesabeva.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_off0000d695.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD695 18384 bytes
SHA-256: ec9fd7bc811180a981d8387202055cec51159b25e35e3dc18f32cf1c4b512634
font_01_sfnt_off0001059e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1059E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011db5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB5 11012 bytes
SHA-256: c946873abeb414552f42991695f0213035eae64824cf01beabd8ec888073de01