Malicious PDF — malware analysis report

Static analysis result for SHA-256 8393f6a1e73c203a…

MALICIOUS

PDF

88.2 KB Created: 2021-07-23 22:01:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3025e5741aa7b6290f31c459621c7dd1 SHA-1: 5f8e13982a440caa1ae135fec6b919c4196d75c9 SHA-256: 8393f6a1e73c203abd5cef05c13ed79ba0e8947fdb47c82cbb2b0ec912c599cc
136 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress upload directories and disposable hosting domains. These links are designed to host and distribute further malicious content, likely other PDFs or executables. The ML classifier strongly indicates maliciousness, and the presence of a link farm suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 6

  • 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.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://cycling-software.com/files/file/70593600666.pdf
    • http://bortran.com/upload/image/file/20210624101400.pdf
    • http://adance0112.com/upfile/editor/file/gexonisekutanogol.pdf
    • http://sumnerclassof1976.com/clients/4/49/49b54eafcc86ae0c30eb104ab8b91c7c/File/61901890125.pdf
    • http://nova-auto.com/upload/16406128825.pdf
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/risuluwafamuvojefo.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/00c084917c83521786b523d33d08e45a/mabaxaguvopiran.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf3a587d6a---47453667652.pdf
    • http://a-swiss.com/upload/userfiles/file/28790036129.pdf
    • http://champagne-marc-chauvet.com/images/files/mejudetikif.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16089dd887a406---94082816913.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/160db867e8d61f---zupiwewejelijebudera.pdf
    • http://verkaufs-akademie.com/userfiles/file/duxozozudufokusuf.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c305b0b7ca0---tudasalejukibusaxoxek.pdf
    • http://www.jindatunnel.com/up_files/file/619281005.pdf
    • https://digireg.cn/upload/neremefozisoxaguzo.pdf
    • http://innospectrum.eu/hirlevel/file/35311020113.pdf
    • http://www.amanuttarakhand.org/ckfinder/userfiles/files/73590911581.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c6d3e583532---dewonagetexaxifa.pdf
    • https://ewastexperts.com/userfiles/files/babosojakogim.pdf
    • http://chickendaylacrescenta.com/uploads/files/romogijun.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0a69c089f---xulugow.pdf
    • http://sewakendragroup.com/userfiles/file/69082314265.pdf
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b74021a4de9---wataxukagaga.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=how+many+years+does+it+take+to+become+a+orthodontist+assistant
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1da.bin
230bf82ffaee1ca1e3185c83a8de755f5bc8bae1c258dcd1c1e91d38b4acb400
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DA 16992 bytes
font_01_sfnt_off00011e25.bin
6552ee81e9b8678baa399603d939efc6ad3ae7f7fed2ba7ed32e0d35e95ece69
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E25 11012 bytes
font_02_sfnt_off0001379a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1379A 16792 bytes