Malicious PDF — malware analysis report

Static analysis result for SHA-256 780478fc1e1fd374…

MALICIOUS

PDF

81.2 KB Created: 2021-10-07 00:46:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9a18db917adb8d70a53e3e1708432148 SHA-1: 571ba32ed445aba767efe09a9981bc5aa2e00887 SHA-256: 780478fc1e1fd3740af5ae6f064f9699e6b8c2b40bc4d39ced6a73121de578cc
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://sapporopools.com/contents/files/99483743815.pdf In PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/80404710804.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210905105155_1227063318.pdfIn PDF document text
    • http://commsoft.nu/demo/ktb/wsmbilder/files/98392474896.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/16707713974.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/nosipitalamedozafatav.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/xobapaguj.pdfIn PDF document text
    • http://solee56.com/ckfinder/userfiles/files/nuxawetegakener.pdfIn PDF document text
    • http://yuanjiangchem.com/upload/files/sefuribilalogegerezu.pdfIn PDF document text
    • http://onyx-innovations.com/assets/ckfinder/userfiles/files/sipojodape.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/55536829634.pdfIn PDF document text
    • https://xn--lenachatka-57b.pl/uploaded/file/xelidotaruk.pdfIn PDF document text
    • https://nexusmediation.nl/files/91633647146.pdfIn PDF document text
    • https://hoya.hr/UserFiles/file/40902576618.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/13599812858.pdfIn PDF document text
    • http://www.smpnuenen.nl/images/files/kasudebatag.pdfIn PDF document text
    • https://lideregitimpaketleri.com/calisma2/files/uploads/relijagozoxukoxoguku.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/91567845093.pdfIn PDF document text
    • https://dveropolis.ru/upload_picture/fijiwalazem.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/nagixilojipitisonit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=chinese+calligraphy+font+free+downloadPDF 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_off0000d3c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3C5 19184 bytes
SHA-256: fc86009e9f0684fbdbde59c27bf4a635541dfa6103acff758e87f60dfb273c16
font_01_sfnt_off00010596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10596 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011dad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DAD 11132 bytes
SHA-256: 60647a26fa31196a7af28db921b84109903e5764a22dc63b7733f490eba111ed