Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4f546a02188d83a…

MALICIOUS

PDF

85.4 KB Created: 2021-09-24 11:58:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cfba5dc853eb635b82af55ea52f2ce3b SHA-1: aea57b67d0f986be47f98afa0cb3a6e85db5d654 SHA-256: c4f546a02188d83a28e5d16655db3b943deab5506d5817bf5bc62b113506e61f
96 Risk Score

Malware Insights

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

The PDF file contains a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. The ML classifier strongly indicates maliciousness, and the structure aligns with a phishing or redirection attack. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://aaz.sk/editor_uploads/files/31591704819.pdf In PDF document text
    • https://mongolia-volkslift.com/uploads/files/tobebebomelasopinedi.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/af7877a61ad8ccdd591168eb8b389b69/7009073587.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/84997031276.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/kodurajepobujikakefu.pdfIn PDF document text
    • http://www.udelimpa.es/ckfinder/userfiles/files/mofabuka.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/52521109270.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/xoxirefol.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/32a948c11c315fea71c0707b57142eb5/96773965447.pdfIn PDF document text
    • http://kimyasaldubeller.com/upload/ckfinder/files/50107266976.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/557r944p523dtd2l04d1brtkv3/6427280116.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/161470acf15893---xefobizatazonanuwegaja.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/25943324737.pdfIn PDF document text
    • http://s13cf5ef.alojamientovirtual.com/ropalaboralbarata.com/userfiles/file/30647022420.pdfIn PDF document text
    • http://esteticka-stomatologie.cz/files/content/file/xebeva.pdfIn PDF document text
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/84036818199.pdfIn PDF document text
    • https://agros.net/uploads/file/41045809577.pdfIn PDF document text
    • https://agriturismoilcolle.org/userfiles/file/80632417429.pdfIn PDF document text
    • https://senegal4d.com/contents/files/mugotudogedijuzitowor.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/36480602028.pdfIn PDF document text
    • https://akgoz.zemta.com/uploads/files/40828244599.pdfIn PDF document text
    • http://thongthien.vn/upload/files/namokodijuwulid.pdfIn PDF document text
    • https://livresdarts.com/ckfinder/userfiles/files/33963801480.pdfIn PDF document text
    • http://nomayaku.com/userfiles/file/zeguxidobodutap.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/kadekufedi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=best+android+app+for+audio+editingPDF 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_off0000ea79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA79 10780 bytes
SHA-256: 007374faaf2236f86e63614f889b563f5951498f567c4f045a58916894d86cf0
font_01_sfnt_off00010342.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10342 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B54 17168 bytes
SHA-256: 35763bc5c21c30d7eab8e1df4227fefc492c3ba29a0db452a48387d3b78d3f8b