Malicious PDF — malware analysis report

Static analysis result for SHA-256 91dfc48207564075…

MALICIOUS

PDF

84.0 KB Created: 2021-10-16 13:45:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 61af1b7097827abba0940ecca6fab893 SHA-1: cb97df5c178074bd551d5b64f11da042a2f230cb SHA-256: 91dfc48207564075ac45fed01f67a52c242cba7d5e2b67020f40081b3128390a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable hosting and exhibiting link farm characteristics, strongly suggests a phishing or malware distribution attempt. The document body, though heavily obfuscated, originates from wkhtmltopdf, indicating it was likely generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://garglob.ru/uplcv?utm_term=best+money+making+missions+gta+online PDF link annotation
    • https://accuratesearch.com/userfiles/file/86963279056.pdfIn PDF document text
    • http://iaestedresden.de/userfiles/file/voguwenebifekimuzi.pdfIn PDF document text
    • http://maivietnamesecotati.com/uploads/files/rujomorolagu.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/fadurob.pdfIn PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/binugodan.pdfIn PDF document text
    • http://dajuicebarus.com/uploads/files/nebofulemejedepikubawad.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/78338192364.pdfIn PDF document text
    • http://termocity.by/pics/files/22854437383.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/mubovatubelirowadapiju.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/13965649895.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/38552118650.pdfIn PDF document text
    • http://www.saletime.gr/admin/fckfiles/file/nibugiba.pdfIn PDF document text
    • https://kirmatas.com/userfiles/file/vofubu.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161489282da3f2---nipisilitugobugowugolixaf.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/53476027662.pdfIn PDF document text
    • http://hanaelectric.com/userData/board/file/86674586511.pdfIn PDF document text
    • http://gps-tw.com/CKEdit/upload/files/34052324717.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16138c25f17d39---31739088115.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/file/pukajidob.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/25672448185.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/22426434056.pdfIn PDF document text
    • http://haliburtonhighlandsheritage.ca/userfiles/file/nubugewuwibodalekizufelu.pdfIn PDF document text
    • http://wsospice.org/uploads/userfiles/file/file/10117425979.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/85842295553.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/47513252140.pdfIn PDF document text
    • https://booburger.myagenda.cz/pictures/editor/files/97830547254.pdfIn PDF document text
    • 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_off0000e4b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fcca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCCA 10608 bytes
SHA-256: 0632900537dd1fbe870160cb75552ed9654ccb2b680fa50215eb86398037cf58
font_02_sfnt_off0001151d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1151D 17416 bytes
SHA-256: c6bd4f4a5be00f587838bf01a4d9917171145e486a2bbc81ec1cdc9cb1dfa950