Malicious PDF — malware analysis report

Static analysis result for SHA-256 55db2bad93314de3…

MALICIOUS

PDF

73.9 KB Created: 2021-09-07 04:50:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a9fffc3da07a9b0435371d1c59947e10 SHA-1: 49c1d1a32f2c3ee6546492cfcec6d71685bc3426 SHA-256: 55db2bad93314de3df46417774042e28ee07e0bd2b218d05d0ec0dd93e970e2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicative of a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the URL structure and heuristic firings point towards a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://ketchas.ru/uplcv?utm_term=agnes+heller+livros+pdf PDF link annotation
    • http://maimungkorn.com/UserFiles/file/89378237496.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083888a5a59c---5660223055.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/ae971e9dff857ce87f5e8f616b52b138/gekogudirelifalumerufemu.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/magalisaxakaboburoler.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160804b24caa47---jufibadanexoba.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080324c8e8b6---fikabulubi.pdfIn PDF document text
    • http://mvclassof1990.com/clients/8/8c/8ca0ba2c7a07c5cd1f21f9fc323c16c5/File/kowepedesidunimofegijapis.pdfIn PDF document text
    • http://polenes.cl/userfiles/file/34999567008.pdfIn PDF document text
    • http://guowangcable.com/d/files/89010047814.pdfIn PDF document text
    • http://natur-pet.cz/webpagebuilder/ckfinder/userfiles/files/jopajesopixegakegum.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/snsj4mcun3rnstsbts6hjo539s/mekukitegugibufijapenasu.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/8179187265.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/31663083556.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/dojigujusuzobawenewevotox.pdfIn PDF document text
    • http://duepassidalcentro.it/userfiles/files/15739075415.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/27583750406.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/22202353198.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/1a8b4daccea5816e84d97e316fd78e25/memibutuzubi.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/ganuma.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc08978c7d0---famefivoxixazuvalu.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_off0000b96a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB96A 10564 bytes
SHA-256: dc60538442cdf5eabb391792d5fc7e29dde958fe98acdb973a96668f6afeede6
font_01_sfnt_off0000d132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD132 18828 bytes
SHA-256: a3466d9ceb1574d1d1abc951780fbf4137be0b4d98ac7cc33a46426aba0ebba3
font_02_sfnt_off0001028f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1