Malicious PDF — malware analysis report

Static analysis result for SHA-256 44e5bd40cd3253eb…

MALICIOUS

PDF

78.1 KB Created: 2021-06-10 15:56:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 88bfc01998512c72f0b5b76145433f0b SHA-1: 20178daefeb8bdac56f42725bb95193df454a9c9 SHA-256: 44e5bd40cd3253ebe7080da2a765da61376bf62697ac03eb790230bb0d8c4567
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm for malware distribution or phishing. The ML classifier strongly indicates maliciousness, and the presence of embedded URLs points towards an attempt to redirect the user to malicious content. No scripts were extracted, but the overall structure and URL patterns are indicative of a malicious distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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://coretry.ru/uplcv?utm_term=ielts+writing+task+1+paragraph+structure PDF link annotation
    • http://drapikowski.pl/uploaded/fck_files/file/41458907696.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/cbdb35997e3b490ec1d885af8a65965c/namitivoropabo.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16071675433402---4194217851.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/57huftvv9c0oabrdpo85vj0mp1/kevisuzomi.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/h507i1mmpij4cjnubphe0kvp85/38296097974.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/kakizisegabutop.pdfIn PDF document text
    • http://soft-pro.hr/upload/datoteke/31453273877.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078fa23dcbdc---zepalibusafez.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca4359fa95---88544966097.pdfIn PDF document text
    • https://tavio.ru/files/file/numafumetu.pdfIn PDF document text
    • https://childrencareandliteracysociety.org/userfiles/files/xukuwapatasejaredekipa.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160aca5ad5543b---59330288436.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/u2f84ioe3bnj0oqete44hh8gm1/38818840621.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/f6fsedlg6edovolmfgcke0ts01/24602756945.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a28557f3ede---28424328794.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BF 5340 bytes
SHA-256: 7470f85f34cfc1f7a1a1c20fc867f3c171978c8cb984cef774aecfa4b5c314b7
font_01_sfnt_off000106fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FC 10520 bytes
SHA-256: 26c2449c48e9625a55b47bc0b89b3fdbd28754cc5b51b019b2af442097542bef