Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b3a168c7a91960…

MALICIOUS

PDF

81.9 KB Created: 2021-09-07 19:35:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 547f06da606eaff54216b25627770fb1 SHA-1: 83c0aa39cb04113ee97ccd61644e8a6eb1cd2d7c SHA-256: 73b3a168c7a91960c3955a747b31ef00abe8658c38c14be4cd85d36769abc672
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, pointing to a pattern of distributing malicious payloads or phishing lures through these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/8071e3720f7dfb94ebdf69838c713770/62010862444.pdf In PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/284c016f1435aafcbf893386a8b290fe/fopizizopuzexosa.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b7aa87f64---11784614519.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/m10ocm4q3a3be1i478k1dmi0kl/47034925920.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0714/29530a1354c54c7085b36328e07c978d.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/192qib2oc955hnj8ooo8j5lk87/6924104962.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/37873138851.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/75320877563.pdfIn PDF document text
    • http://bronia.org/userfiles/file/wadogewajiwinu.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3b524f089---94097321535.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/5970089837bce5bde15e2d51b039eae5/15930659666.pdfIn PDF document text
    • https://fallahi-sch.com/userfiles/file/23425552260.pdfIn PDF document text
    • http://www.truca-taoules.com//ckfinder/userfiles/files/zelifugebuj.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7bb00d5f8---gabiwoguzegazusavo.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/rsfhkenmssd3q3cvcivnc7d0s4/wodogodijejin.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/rigezumetafatewozegorodu.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/16079c7f3d4cd7---vipasegenusi.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/ndrqccc3ufsehntqehha4a5qvb/94452481392.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a22a369c7b7---nexuvapo.pdfIn PDF document text
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/7839b3dde541c90a9aa0ea991a2d93a1/vurozelulenimozulopib.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/zuvonetigowib.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///dipimoxulujufamidinaje.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/kapitosexibavoropega.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/fodinatidugoreb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=default+pdf+reader+registry+keyPDF 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_off0000db30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB30 17604 bytes
SHA-256: 7f22bb6eef6e64f6fb893135bdb773f414faaae8b51770f1db774f488942433f
font_01_sfnt_off000108b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B1 10756 bytes
SHA-256: 6a7d9afa940285da912a118d5d725e24c82c430d403aeffd66ccfae161b46b85
font_02_sfnt_off00012162.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12162 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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