Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c5f3636d0b94a21…

MALICIOUS

PDF

72.6 KB Created: 2021-09-16 23:19:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3f2eb98f5f45f9fc723c3fa0644353b1 SHA-1: 7616097d599d4a6c7bd81c7f2e41dbc91bfcf405 SHA-256: 7c5f3636d0b94a21e18ff0b76b9f733a1914f1e3b22b95abd19717d8d1ebd350
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by ML classifiers and ClamAV as malicious. It functions as a link farm, containing numerous embedded URLs pointing to other PDF files hosted on various domains, many of which appear to be disposable. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such domains, suggesting an attempt to distribute malicious content or phish users. The presence of external URIs and the link farm structure strongly suggest an intent to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

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 http://spy-military-labs.com/userfiles/file/39562223761.pdf In PDF document text
    • https://mimpishio1bet.net/contents/files/tosenadisuvedadonajero.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/5390262295.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a13b23f91---93607921790.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109030252286898.pdfIn PDF document text
    • https://yifff.se/userfiles/file/26672330573.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/73008293810.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a0d0c52de---towajodadonetolir.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50777340933.pdfIn PDF document text
    • https://shinko-tw.com/UserFiles/file/89447453378.pdfIn PDF document text
    • http://kryotherapie.net/neu/userfiles/file/13310374606.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/37171934064.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/xuladobotu.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/73104602408.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/faminatilug.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109032214584448.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/dijimatejupewek.pdfIn PDF document text
    • http://skupka23.ru/upload/m/dimaditazumotemasijif.pdfIn PDF document text
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/92794158192.pdfIn PDF document text
    • https://kaparatt.com/images/File/86110489039.pdfIn PDF document text
    • http://air-con.ru/upload/files/gugomigaxavomonaja.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/37146794918.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/3644635071.pdfIn PDF document text
    • http://xn--80aafjbaeihgganggf9ajkncugh2a.xn--p1ai/pict/file/gezivogarawarolamoridokuj.pdfIn PDF document text
    • https://12shio3.com/contents/files/jisagulakefubuj.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210906_927A5EF91BCBED9A.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=sapiens+a+brief+history+pdfPDF 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_off0000ba95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA95 10876 bytes
SHA-256: 521e5b0f0ddda2f7bcecbf8359d050909174174c57f5212b622f8263db571a0d
font_01_sfnt_off0000d36f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD36F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB81 16112 bytes
SHA-256: b54357b5d80754cafc3a7c689a749520a58f2b9d3b3d1b427cc6a5f0b55b786e