Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1d011bc456f68f0…

MALICIOUS

PDF

75.4 KB Created: 2021-09-13 01:31:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4adf490cc75b690202b26cb34bed9cc2 SHA-1: 906be6272534305781717a9a0d356dd008f481aa SHA-256: a1d011bc456f68f03cf3d09d7f3a4515700bded3f037976250b4c893e16ca9b1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the structure and link farm behavior are indicative of a phishing or malware distribution lure, likely delivered via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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://tranduongauto.com/app/webroot/files/images/pages/files/90568806079.pdf In PDF document text
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/witigesazas.pdfIn PDF document text
    • https://geniodelweb.com/file/75528839285.pdfIn PDF document text
    • https://ltes.tw-goods.com/UserFiles/files/lazedifaxorulib.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6ac3eb8f4---potikif.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/8f94fb3367ca08e8f973174efc5645df/madekoda.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/798f658143fb50af0de3325ee03e7bdc/88383074825.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/figexeno.pdfIn PDF document text
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/lunexux.pdfIn PDF document text
    • https://marblobathware.com/app/webroot/img/files/pezabutadabagosineta.pdfIn PDF document text
    • http://investbuild.ru/var/upload/file/61455545337.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/poretiwaj.pdfIn PDF document text
    • https://venefoil.com/ckfinder/userfiles/files/78490445284.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/ed1e1c42ff7374ff0dbac4eed7fb81e6/12844782085.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/l8nof7l2fo3an40uiqcb6anva2/fibokofebutap.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/65145449820.pdfIn PDF document text
    • http://samtle.net/ckupload/files/77945397382.pdfIn PDF document text
    • http://shanghaicruiseparty.com/uploads/file/19988278505.pdfIn PDF document text
    • https://juraganmonyet.com/contents/files/67771049977.pdfIn PDF document text
    • http://tlw.ro/UserFiles/file/vuxivipenetil.pdfIn PDF document text
    • http://i-akparat.kz/ckfinder/userfiles/files/26081208631.pdfIn PDF document text
    • http://lignumweb.com/site/webroot/uploads/files/madumejejodelurev.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/31537947631.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=where+can+i+watch+rangoPDF 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_off0000c38c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC38C 17076 bytes
SHA-256: 12996138853dd46542eeee652ea1ee83f27f3297c99fa968b7f3234091efcf9f
font_01_sfnt_off0000f05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05E 10376 bytes
SHA-256: b3c2fea633b939180ca32b4911a3e6c0c1ff2c070cf8ada084eec17edcb27790
font_02_sfnt_off000107e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1