Malicious PDF — malware analysis report

Static analysis result for SHA-256 5efb583b11092854…

MALICIOUS

PDF

82.8 KB Created: 2021-09-03 09:30:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5ff98e6476313983f72343683270e522 SHA-1: 0d9a7dbaa2cbb01291c57b6d7a3efdbdd136b69c SHA-256: 5efb583b11092854cd8e051d5e5d4c54dc0d9d16bc320ade26bb08a8a6ab9f57
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160840fd30e69c---kudulusabozugof.pdf In PDF document text
    • http://anysoldierfundraiser.com/clients/a/af/af293656121fcb8b60a8c910089dd81c/File/50638837211.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/gliqq9vj6p6tvcfuc0s6r0cr5i/5281900970.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/vozijobukisanemedakuvu.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae0da3192b---36855839754.pdfIn PDF document text
    • http://954move.com/clients/4890/File/seritar.pdfIn PDF document text
    • http://blackshirts1962.com/clients/f/f2/f245580d3072b78cda2271cf7a7e3f61/File/soxibijusofiperuf.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/sijukitupuwukobuzeselazi.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609451df2d33f---levosowafusosorotexepu.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160d30db20462b---debatelaxi.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/71066833976.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-7-7/20210707212641345119.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/2a363d486362b5ae949220d5d0a0b616/90719720012.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16107e3539708b---lifagemepiwi.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/eabfe4a48b3c56e29e6238f7516a0810/33822772848.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/lewimowofatibo.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/5069c65680c66bb1399b7d802cff8971/74492237720.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/gemonekibufirelopiwilat.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/vosibag.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/4c56bad459d5a8dd1288c17b91f79056/fibufelom.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d0d4748b56---28280600234.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/mede7v3cobs6si5havd8851k63/lotujavuxiri.pdfIn PDF document text
    • http://marinapogon.pl/upload/file/dexufifusepavegilepadizap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=add+image+to+pdf+using+jspdfPDF 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_off0000dea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA9 17596 bytes
SHA-256: 9d103f7ebd2408fe45e23da2e44c5ad51d506dfeb6795b26e5be3627721fe194
font_01_sfnt_off00010c8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C8C 10904 bytes
SHA-256: cefb6d5bd7de44870b04c4de05132c3c43530f4a4b5e256be7856fe61427ca35
font_02_sfnt_off00012597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12597 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1