Malicious PDF — malware analysis report

Static analysis result for SHA-256 903e36e4aee7d001…

MALICIOUS

PDF

72.4 KB Created: 2021-09-25 10:46:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f857ea9a1ba6ddbfddb02c3c93c8f76b SHA-1: c6a1486a0e0d6441bde09fcbc5e862d8126c8be9 SHA-256: 903e36e4aee7d001fbb36e949927b303eee4feded2fcb0c128c8f6ea8b471acc
156 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. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload storage or disposable hosting. While no executable scripts were extracted, the structure and URL patterns are indicative of a phishing or malware distribution lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://adsbudget.net/userfiles/file/46562523850.pdf In PDF document text
    • http://helenhotel.vn/upload/files/gomufozuwenijan.pdfIn PDF document text
    • http://giasudaihocsupham.com/Images_upload/files/tozaresimajog.pdfIn PDF document text
    • http://haiannweb.com/uploads/files/51682757128.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/56072924754.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140930e0e3a0---kiteranifolepaloforuj.pdfIn PDF document text
    • http://rideco.hu/upload/file/25659888037.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/62610586315.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/runadasaxi.pdfIn PDF document text
    • https://at1apigroup3.com/contents/files/mopubagadokama.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/37086781829.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/wajutiroditujurarib.pdfIn PDF document text
    • http://sameiroeventos.pt/ficheiros/69118959897.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/11704998263.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/610ldb6ojfpnsa7sb0lsljklj2d26hak/tuxabasevilasuvam.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210923110110.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/25pdun7oehnekt10d1gegmb8u4/gaxow.pdfIn PDF document text
    • http://khyljg.com/uploadfiles/files/ruwukujixesoxal.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614082eb705ed---15730723841.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/igidu7kgp70ndg8mjv85r040p4/92287587547.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140cefd745cf---95421477663.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/26010540631.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+add+obb+file+to+apkPDF 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_off0000b3c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C4 10428 bytes
SHA-256: 01db896ad79abd773b2c5eb1c1bdfd990273cf1fb9faa611f80c67ff28a6fa19
font_01_sfnt_off0000cb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e35f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE35F 18124 bytes
SHA-256: f4c983759c8ce0d1ec878fd0ea297accecf987618ea6e16fdf97657e8b3df840