Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f0e35ada477013…

MALICIOUS

PDF

86.7 KB Created: 2021-08-30 07:18:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c82987519458660e044a276e104a933b SHA-1: e16d79fb241762ddf6c2587076af332b1b887b03 SHA-256: a6f0e35ada4770136fdbf455c8cc32e2561582218b3e3af13bd498d7e291e8fd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV and an ML classifier as malicious, specifically as a phishing or trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://flardochform.se/userfiles/file/pulezezidikozawefo.pdf In PDF document text
    • https://sleepthai.com/piceditor/file/51889605885.pdfIn PDF document text
    • http://abwbaltimore.com/uploads/files/93773101525.pdfIn PDF document text
    • https://tcremich.lu/files/files/45817269292.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612bb771e0ad4---legipokowulaxisara.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16082838bf1b4f---roxanikivipeposina.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8b79a60e28---nogadefadagopuwezez.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/fomewudobakutisa.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/39311e647f7a03181ba211a4ff7288b6/50413477476.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/dizigalofupufin.pdfIn PDF document text
    • http://agiteam.org/clients/b/b0/b0c4817036ef1cb73596cc935f3fa86d/File/82574136969.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3b4225bb1e---junokirifoxurobaxigu.pdfIn PDF document text
    • http://lws-realestate.com/userfiles/files/52146731034.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a96f6504529---63769104303.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/81288505041.pdfIn PDF document text
    • http://gabortech.com/admin/file/zagolamidulidafuragamarik.pdfIn PDF document text
    • http://maternites-catholiques.org/ressource/site-image/files/52308667982.pdfIn PDF document text
    • https://baptistfriends.org/media/nanuxalutubodamusi.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d69ad42afbd---22877914643.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/3460a34409805d8a79463a59f17a04b3/70493514738.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/562d66b411b18382352558671d28ce26/rejifonenasuko.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/38791064237.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b20c991e97---somol.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/fabinafetudurejaked.pdfIn PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/dizukuseg.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0b0d45d00d---nujesetegilovopi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=beautiful+lines+for+brother+and+sisterPDF 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_off0000eaf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001030d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1030D 10744 bytes
SHA-256: 1958b8f0f0fdf6c875ceecdce9a61abf7edfa8a5eb332c40250e4a627f9d14d6
font_02_sfnt_off00011ba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BA5 18388 bytes
SHA-256: eee8988a37c3e62450994adedc3e1a5646901c8c685e43af1abf62978ac08652