Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb3bb54e06ae08a3…

MALICIOUS

PDF

70.7 KB Created: 2021-09-24 21:03:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8e91a724be55f92083aa86d241c15905 SHA-1: 9e6b4be493bc8b2fed56c7f29bef6fdeece92038 SHA-256: cb3bb54e06ae08a37224a05b2ae6155f7fb091ef36224fe0a02f1b4e25dd8852
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV and an ML classifier as malicious. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of external URIs and link farm characteristics suggests an attempt to redirect users to malicious content, likely for phishing or SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://mahae.hu/files/files/6770446318.pdf In PDF document text
    • http://vasekurzy.cz/userfiles/file/xefupuwexafekomojubapu.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/92102835308.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/42746169627.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/18353477128.pdfIn PDF document text
    • http://xn--80aguejfegacgj0ad.xn--p1ai/pict/file/dagasedusiwerideze.pdfIn PDF document text
    • http://itps-group.com/uploadfiles/file/wogaxeribefugep.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/mulogibawazavonedozexoj.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/64548534971.pdfIn PDF document text
    • http://thegioimaychaybo.com/app/webroot/uploads/files/kidalurogaxifoko.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/nixobebanigajufeda.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/21082685187.pdfIn PDF document text
    • http://artemon.nl/userfiles/file/93126754583.pdfIn PDF document text
    • https://guclupin.com/calisma2/files/uploads/23858589337.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/4e7625c498537aabc8dd0361a15e8a36/nufizilotomadivoxokax.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c992e4913---68104160400.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/tixonatidezi.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/5387qqdqc0fbfh7d0cigs7giv7/takevapoxikudejunefexoda.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/33703598021.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/9bb17ccdccfe95d0f757c3f7bdc89930/bijozukirupetufomafodaxut.pdfIn PDF document text
    • http://marinda.ru/pics/images/file/jutuzisudarojanexamen.pdfIn PDF document text
    • http://ecovn.vn/uploads/news_file/93312409744.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/zinivizow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=wifi+not+connecting+on+android+tabletPDF 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_off0000b356.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB356 10616 bytes
SHA-256: 383523a2a4eb9e69ecd979d14c0fc3125d1d25c35db705fdc859022978bd1f91
font_01_sfnt_off0000cb82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB82 16232 bytes
SHA-256: 93c847466124714836451262e6186a5181a1dd2faf6e7f854c1548ef5657e848
font_02_sfnt_off0000f4f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1