Malicious PDF — malware analysis report

Static analysis result for SHA-256 851235c89258cac7…

MALICIOUS

PDF

84.2 KB Created: 2021-09-05 18:05:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d3a531f8879095f4c8829d2517e202e1 SHA-1: 3cc0f3fbfee097757cf1439c958033ebc145224d SHA-256: 851235c89258cac797ed809c234070b10aaf5d6f0a3932509743462b67a61c96
156 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to potentially compromised or disposable hosting domains. These links likely serve to redirect users to phishing sites or download further malicious content, aligning with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://purofirstli.net/userfiles/file/kupobebarodatapimepaxaro.pdf In PDF document text
    • http://feach.ie/images/uploads/file/76463630206.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/14536498048.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27554606913.pdfIn PDF document text
    • https://www.sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a931b6bf7d1---34685631466.pdfIn PDF document text
    • http://anandtouristcorporation.com/uploads/67915956034.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/lv42g9hh0gju5du01qbg04oc26/fetibenuladiw.pdfIn PDF document text
    • http://allycatering.com/userfiles/88027213523.pdfIn PDF document text
    • https://ienter.bg/files/xixogijubuwexapuzamekovaz.pdfIn PDF document text
    • http://nikacarpet.com/My_Project/Hamishe_bahar/ahar_img/files/73830580076.pdfIn PDF document text
    • https://porterbrothersltd.com/app/webroot/uploads/51477295703.pdfIn PDF document text
    • http://hc6999.com/userfiles/files/33554964619.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/32pkf381230rb8hqkjln0q6jd4/wesanilonusepawudisavin.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/larfmepch2rsm8ro4mtgqbbkkj/78870640815.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/3d8c4eaf4d16c091c64a98e6ffff401f/75811831459.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160ca7e9b29ea0---vukivun.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/8251405894.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/98523875689.pdfIn PDF document text
    • http://dvarenda.ru/upload/file/54145568200.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=preparation+of+balance+sheet+from+ratio+analysis+pdfPDF 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_off0000e2c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fadb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFADB 11140 bytes
SHA-256: 05bd4c526d7f2d7bc77f76ac87107a17cb5d68d370e95095c78c2c978e6f40b3
font_02_sfnt_off00011472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11472 18036 bytes
SHA-256: 81e5a65e6c99d73cec2eec3661d98b59605f5adcd6ac22ffff69093b09f3c64e