Malicious PDF — malware analysis report

Static analysis result for SHA-256 6399ce8e249f4b81…

MALICIOUS

PDF

80.1 KB Created: 2021-09-04 15:12:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a57500e6e2a5b889e9d6ed7918f7a95e SHA-1: 8ae2032a36408869bb05d686d28a3f8431a7c437 SHA-256: 6399ce8e249f4b810957f2971249f116d02b56a5a1f31d00609be7f270c23a30
156 Risk Score

Malware Insights

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

This PDF was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of embedded URLs and the nature of the heuristics strongly suggest it is used for initial access via spearphishing, potentially leading to further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 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 https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/4b5649a94edf169d825c6569e2ffbd8d/zagit.pdf In PDF document text
    • https://ajitcoatings.com/uploads/86602937125.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/loxirokagumosodiwipe.pdfIn PDF document text
    • https://dienhoanghean.com/upload/ck/files/mijanexesipiluj.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a84a67ee6f5---tegusesameparopajugab.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/wekegakidir.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/bituxisivetelerofetutezop.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/tomunobulipexigopode.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/9556729116.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/77b976137d891ab79bd28a8367c5616c/movegejev.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc878c0057---7417180570.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dde443c2b32---xokabifowizixazaveseg.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/25951d46aa39d5e420a9632fd96d014f/pemoniruje.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/70028472600.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16079a8b702c40---mikutusamugad.pdfIn PDF document text
    • https://oglethorpeclub.org/~oglethor/UserFiles/file/wezusegorabipakasose.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/zijowimivikupidedives.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/gidajemav.pdfIn PDF document text
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/kodijefugosutularina.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160bfa77a53f7b---70485566375.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/41336042913.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1612114fc6d68f---fukijekelimiburufefexen.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf7834edc8---gugudejijilefezopadusoku.pdfIn PDF document text
    • https://studio-september.com/wp-content/plugins/super-forms/uploads/php/files/e2423cccea85e48b5ee3e387b54f1056/vujozufelod.pdfIn PDF document text
    • https://evboosters.com/wp-content/plugins/super-forms/uploads/php/files/be02448b62da39b0bab9415519133c7f/wonefikaxi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=talk+back+and+you%27re+dead+pdf+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_off0000d067.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD067 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e87e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE87E 10784 bytes
SHA-256: 352d480290dac8144ddd6d704b2d4ece694bc6f4bf1c0d641cc014717b376a6c
font_02_sfnt_off00010161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10161 18772 bytes
SHA-256: 427aa121b1d7252a780e188b6ddeec5f12a9419e817ea3ab3f2cc680e42ba931