Malicious PDF — malware analysis report

Static analysis result for SHA-256 0815665cd0f4f05c…

MALICIOUS

PDF

72.8 KB Created: 2021-09-26 03:22:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0e4b3fba5c2eb7bafcdf22dcd16d23b1 SHA-1: 1bfbc58bd7bd579ba48bf4b555cef308daadd48a SHA-256: 0815665cd0f4f05cbfb633f667513e0943b0dae2fd97d7ec1364a3aeb8ebbd3b
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by multiple heuristics, including ML classification and ClamAV detection. It contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF_RANDOM_URL_LINK heuristic indicate an attempt to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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://medvor.ru/uplcv?utm_term=virtual+global+pubg+apk PDF link annotation
    • https://alice-immo.com/userfiles/file/42745977552.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/13525953431.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/2203982421.pdfIn PDF document text
    • http://www.singchai.co.th/ckfinder/userfiles/files/14789611808.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/45540304694.pdfIn PDF document text
    • http://captainkillmite.com/uploads/files/202109090820422008.pdfIn PDF document text
    • http://nuovartea.eu/userfiles/files/60758190039.pdfIn PDF document text
    • http://aerotechgroup.ru/img/outer/files/39966689901.pdfIn PDF document text
    • http://struttur-arch.it/userfiles/files/mofiperenov.pdfIn PDF document text
    • http://sanruou.com/app/webroot/uploads/files/61731349624.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/fumumexodagadorupej.pdfIn PDF document text
    • http://torgoborud.org/images/file/73935445805.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/pajij.pdfIn PDF document text
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/7378114492.pdfIn PDF document text
    • http://cuuhoatudong.com/upload/files/2525328942.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614167d056e10---31423478110.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210905095905.pdfIn PDF document text
    • http://unewstoday.com/task/userimages/file/mozapeta.pdfIn PDF document text
    • https://macintosh-szerviz-javitas.nuttydog.hu/ckfinder/userfiles/files/xusekomijugoguxawuzem.pdfIn PDF document text
    • https://childrencareandliteracysociety.org/userfiles/files/50508710641.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210916003637.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/bagobilinoxojotonaxole.pdfIn PDF document text
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles/files/50191394926.pdfIn PDF document text
    • https://parkettworld.com/upload/files/98861734998.pdfIn PDF document text
    • http://reestr.fgosvo.ru/files/files/42973414225.pdfIn PDF document text
    • https://rtaadmin.mrv-educationservices.com/content_file/files/zigerolipevinura.pdfIn PDF document text
    • http://baiduvpn.com/upload/files/90441698776.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_off0000b523.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB523 19140 bytes
SHA-256: 5c6c3a4e0f2b3eba45f3a2b83ad5dcda6a8eb5b93d73d60d560870e43d7c68e5
font_01_sfnt_off0000e64e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE64E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE65 10324 bytes
SHA-256: 21469032ad34c2bfc41e24f9243b634614c284d315d068f1aebe9f328856cb0e