Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d53436431561692…

MALICIOUS

PDF

74.8 KB Created: 2021-06-24 00:52:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: a9344292ed8b7c2ebb9af731931d0f53 SHA-1: a2bf3492840f603ba94df0c88610403575c31c78 SHA-256: 1d534364315616929417689e9992c78bda9ceca2a6c6f1154025167999b37cd7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous embedded URLs pointing to compromised WordPress sites. These links likely serve as a distribution mechanism for phishing or malware, aligning with the characteristics of a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://krisoc.ru/uplcv?utm_term=r3+diet+pdf PDF link annotation
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/2037c4b8a776e3ae7d4c660104fc5dc3/54854465689.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160be7903d7cad---92559867138.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609092e03831f---96713023513.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609cdb10ecbbe---vogunanuzowofenatu.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/c15d9f01ead8ab09b7c7c8c0160c832d/tepinajuzutorenan.pdfIn PDF document text
    • http://galgalesh.com/userfiles/file/wodurevugotagesodij.pdfIn PDF document text
    • https://mokhalasati.com/userfiles/files/78975528032.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/7cma4aj1tmd26kcd9lnmbtau50/kezuligalumoveka.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/3e17ff4108354ae319e58ca287a6bf15/tenosifopataga.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/6511aff5e247ac7a7222ee8298b8a95c/vakuzi.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/6fcgnj4l4p8b1ntnv3bck8f40b/niwejosa.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160814a4eb7a84---nigiliraroputenari.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/lvl7bmlpr7cnr7i91flijc39et/28800523535.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16089c09aaa1c2---32572284981.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/74810674000.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/fofuzikuwatuwabejimebo.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d34bc60571---97573217099.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/759c8f61ecd84249b177be9409efc417/xadupewaxakaguvi.pdfIn PDF document text
    • https://puppometalli.eu/file/23925613589.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECEC 4692 bytes
SHA-256: fc443f2970f07f11d309f690b0cd1b5e572e29b1d513c9e0c46761fb0cd7b84a
font_01_sfnt_off0000fd0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD0A 11300 bytes
SHA-256: 8ad142e742d0595ffec2ae79076f2b050f27b75433a270cb7ece2919fee3e4ce