Malicious PDF — malware analysis report

Static analysis result for SHA-256 f45bae22f4f89fd6…

MALICIOUS

PDF

76.4 KB Created: 2021-09-03 11:24:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a4c3125d9cc48d8e7e4b1692c28128c0 SHA-1: bf6a73939d2f0e46cdd00201d1a9df7be7702e00 SHA-256: f45bae22f4f89fd63e03aa5fd7ac266f219f5a300dcde1ecf39a82292fe627a0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of link farms hosted on potentially compromised or disposable domains, designed to redirect users to further malicious content. While no scripts were directly extracted, the nature of the link farm and the ML/ClamAV detections suggest an intent to deliver a secondary payload or phish credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://chono.mn/uploads/userfiles/files/nudovebalemijavo.pdf In PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16075e65d1ee83---41491422071.pdfIn PDF document text
    • http://adbuffalony.com/uploads/files/96396265547.pdfIn PDF document text
    • http://goozzl.com/userfiles/files/joduwere.pdfIn PDF document text
    • http://abwmercury.com/uploads/files/40296425681.pdfIn PDF document text
    • https://curvy.tw/upload/files/82226040266.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/kewasuwozifonejokatedixo.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/xekopalubefitedurisak.pdfIn PDF document text
    • https://savitravel.ro/ckfinder/userfiles/files/wukakit.pdfIn PDF document text
    • http://medica-brno.com/files/93745331497.pdfIn PDF document text
    • https://birudongker.com/contents//files/86391736215.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/83950779581.pdfIn PDF document text
    • http://matras-devison.ru/upload/file/61235911910.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/713f3971167bb97f46a8da331467859b/40820662086.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac63d86920e---15256544266.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/6d1c9a750a50372806de6d8aa03bad88/61885220031.pdfIn PDF document text
    • http://sutphinsgermanshepherds.com/clients/21958/File/56929702745.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/93503531443.pdfIn PDF document text
    • http://mebell-city.ru/ckfinder/userfiles/files/72778690145.pdfIn PDF document text
    • http://erictex.com/ufiles/files/53118576392.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=merubah+word+ke+pdf+lewat+hpPDF 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_off0000c878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC878 16996 bytes
SHA-256: efbbef1fbb4b6119408f0caa6d3929cf2f79f6bdf5e87559b2f8a62fdc50863d
font_01_sfnt_off0000f457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF457 10640 bytes
SHA-256: 981d791e10bab3f3e075cbed3545c82571aa82f524f2d7f7cc003d935cd18dd7
font_02_sfnt_off00010cae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1