Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b369b3155880d9…

MALICIOUS

PDF

86.4 KB Created: 2021-09-18 19:34:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d53fc79bf66724f2026f77f75fc3f01b SHA-1: 7df9524b7b760f21602152fc21c228f01c649d3d SHA-256: 99b369b3155880d94c2b38497bec8ac6bfa826168b50eca0e1ea2a7b518e1342
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier. It contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload directories or are part of a link farm. The presence of JavaScript suggests an attempt to execute malicious code, likely to download additional payloads or redirect the user to phishing 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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://gutachterbewertung.de/userfiles/file/saritekunaxakesomin.pdf
    • http://synfarm.com/upload/files/pirut.pdf
    • http://vectorma.ru/uploads/assets/file/58504327239.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef3cd7dc91---58142228266.pdf
    • http://taispacedesign.com/upload/files/jinusoxol.pdf
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/nemelekuxusevuri.pdf
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161439056dff1b---81403906092.pdf
    • http://cartonwrappingmachine.com/userfiles/file/ramirazogama.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16142def730dea---bigufolotabi.pdf
    • https://jamuiboe.com/webroot/upload_media/vemizun.pdf
    • http://4998horo.gmmwireless.com/contents/files/12627256350.pdf
    • http://topflexsports.com/uploads/33972574471.pdf
    • https://tinnituskozpont.hu/files/63704239152.pdf
    • http://strategie-online.net/catalogue_dynamique/file/20339332930.pdf
    • http://victoryelectricalsupply.com/ckfinder/userfiles/files/nekojugokologevuxile.pdf
    • http://kleinschadenexperte.de/userfiles/file/56772359030.pdf
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/oe0006sav5su82vmkk4d45abni/80298169152.pdf
    • https://linkevicius.com/upload/galery/file/83016727522.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/bewajovepixitad.pdf
    • https://geneolock.com/ckfinder/userfiles/files/70181817983.pdf
    • http://shinaval.ru/userfiles/file/53781741493.pdf
    • https://bobecoingatlan.com/uploads/editor/file/pekunesusaxigonasudarit.pdf
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/6969331850.pdf
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/29cc79df09da0ad9a62e8bbaec4ac4d3/87528413459.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=install+cinema+hd+on+firestick
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea53.bin
ff144fe438becf2b5ec4f964ec1bf8d677d7da34a77498786582116e3a8ebf0b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA53 10784 bytes
font_01_sfnt_off000102f4.bin
5b78afbff223f687d53a4b0090ef31bf73978bdd1b2cf68bc259a1e0cfc96c5b
pdf-font-stream PDF embedded font (sfnt) at offset 0x102F4 18896 bytes
font_02_sfnt_off000133b6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x133B6 16792 bytes