Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cef20e100f66088…

MALICIOUS

PDF

86.9 KB Created: 2021-09-01 12:19:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ac2ce05bdf8a539d327ca7d0276a5b5a SHA-1: 0178031eb50733470b05f40dd7b8eaab134c638b SHA-256: 4cef20e100f66088d10a41368d4ecc851f0bdf01d72d7076cc5653b782e72d6c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple compromised upload paths suggests an attempt to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/9r9nct4gt23uqd48b37feaakl8/nowajipozigawukig.pdf In PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc93b9a1d5---45413889493.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/cs6ae34ml40qso4f9ec5g6nbqd/tovorulimunowese.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/7b7ad049e265f0a6f35fad0b3c72aaf3/gokivufoxukasawemif.pdfIn PDF document text
    • https://airbays.com/userfiles/file/melebifanuwevezevevuvubuf.pdfIn PDF document text
    • http://slsnn.ru/content/file/73733844177.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d1897fecdfe---12000426147.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/bacda08295ee1046d6bc201c0519f1dc/jizewulufaniwemixijuwe.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/ehb7r01ahfbq3f0gimii8iqlm7/temovaxagaganevefolopono.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/3915094075.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16094fecd6739c---japabowitawudara.pdfIn PDF document text
    • https://rajatotogroup2.com/contents/files/notipimujazes.pdfIn PDF document text
    • http://sity-luxe.ru/userfiles/file/lerasutut.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/muvubekibejuviwo.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/d66b89899f54f611d98410c9ec3b0363/zonafibapuw.pdfIn PDF document text
    • https://gotamsui.com/ck_imgs/files/kowivikivogo.pdfIn PDF document text
    • http://jilienjrubin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/patek.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/100fba62d6efafabb0e8f8f8e50b2e85/venafesixonuduza.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/42578373754.pdfIn PDF document text
    • http://sh-ruiyangcpa.com/userfiles/file/2021-6///202163534573524.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/c636094e9f719e16895da90e511656be/79146263718.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202108030352348091.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612553b480e68---nosim.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/wagoran.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+many+meters+is+once+around+the+trackPDF 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_off0000ec0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001041f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041F 18652 bytes
SHA-256: f500b945267680483d78fe94f33005d6d46118c2504ab638414e5173cb9228ba
font_02_sfnt_off000133ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133BA 10972 bytes
SHA-256: 64f35b1984b971a75084b44511e7e58e4d951c59a95df27a0a1616adac727a26