Malicious PDF — malware analysis report

Static analysis result for SHA-256 f13a2468a383184c…

MALICIOUS

PDF

86.0 KB Created: 2021-09-20 12:29:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a41b4fc8e042e485707a23d2721e4cf9 SHA-1: bc721c501d9e509411d5a2beb95421d878d3e58d SHA-256: f13a2468a383184c5a22979bfffb04da7cc96502818bd1046e2734f97bab9df7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also strongly indicated maliciousness, specifically classifying it as a phishing trojan. The document's structure and numerous external links suggest an attempt to redirect users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • 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 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://centaur.vri.cz/docs/files/fofit.pdf In PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/40e12775130ea9b8c6027118bfc3e619/91003260850.pdfIn PDF document text
    • http://lycee-elm.info/userfiles/file/wuvewogade.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/eeng4116600qhnv10k78vs3ucq/60823522033.pdfIn PDF document text
    • http://unibeauty.com.br/ckfinder/userfiles/files/xopobuje.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/738b5849755a5d29ba0a8bfcca3a41c1/mowilenozotibugiboter.pdfIn PDF document text
    • https://vietrocknet.org/app/webroot/img/files/jojazivapogi.pdfIn PDF document text
    • http://boonfagrandhome.com/user_img/files/gunorepelebabom.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/67540681952.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/55311834830.pdfIn PDF document text
    • http://fueandhair.com/userfiles/files/xadofepu.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad5cc30551---fikokuginalineri.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/30865942676.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210918_BA4ADBD1226B197A.pdfIn PDF document text
    • http://dkyangmei.com/uploadfile/file/2021090719445273499.pdfIn PDF document text
    • http://madonnina.info/userfiles/files/jonegaponamobenatogajen.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161459accb3b2f---daforimigonakedizifixasup.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/sidolenazuxusub.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/94473705791.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/damumonegurele.pdfIn PDF document text
    • https://redengewinnt.com/userfiles/file/50536919390.pdfIn PDF document text
    • https://riwg.in/userfiles/file/satasi.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1613f841b2e0a1---98872720024.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/93832174596.pdfIn PDF document text
    • http://izumrud38.com/ckfinder/userfiles/files/31940757448.pdfIn PDF document text
    • https://vientangluc.com/upload/files/25257302343.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=apk+alpine+linuxPDF 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_off0000e65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE70 20240 bytes
SHA-256: 9025ccf9b65d5f961b47387da85619a5de009235a174102d9bc858b18d6f798f
font_02_sfnt_off000133d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133D7 10036 bytes
SHA-256: ec4103a4f3ffda53a9a271da1b7ebe7720e80f708f50276ada4b08b45780317b