Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecbc316c389fad5f…

MALICIOUS

PDF

79.5 KB Created: 2021-08-03 13:21:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 71d075097c772fafd6bae026b607885b SHA-1: 4b05dd19cd79f602aa297477edfb7aa0f127c176 SHA-256: ecbc316c389fad5f33ad3f3ea4ba8bb7be764d48ab73e853b55c5354452967fd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a large number of external URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and URL patterns suggest an attempt to lure users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://smidgel.ru/uplcv?utm_term=descargar+libro+pnl+pdf+gratis PDF link annotation
    • http://tehpromyar.ru/media/file/70645997406.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c07735eeaf---7526063024.pdfIn PDF document text
    • http://sibmetiz.ru/upload_picture/49182258327.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/59731493496.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/fe9fmchfja9bft3hofarmflkk1/tabategawuvubesego.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/51551873193.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/vse8feg74i0s8lm3aef7o4u90c/68617374643.pdfIn PDF document text
    • https://egf.tw/test2/images/file/79545943045.pdfIn PDF document text
    • https://trimix.bg/UserFiles/File/69855473274.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d35aa78db7f---wexizuxapovuxasidejaboj.pdfIn PDF document text
    • http://techscreening.com/userfiles/files/titefazoxugo.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/74849035767.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bee707239ed---takigaxu.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160864f6ed3bca---25271914386.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a1206c96cda---nusikemirerimi.pdfIn PDF document text
    • https://mides.vn/images/ckeditor/files/38386853022.pdfIn PDF document text
    • http://altinay-law.com/images/file/logaxoparawojewavipedurer.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/texireduged.pdfIn PDF document text
    • http://rowanfamilyreunion.com/clients/28915/File/zatixoxoraguzupefef.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/11dg1j28qnuf53lcefofg3ig3s/73184420174.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/094e929f15b2d6ddc585531b9e00cf1c/fekusugujixuwewa.pdfIn PDF document text
    • http://herve-coiffure.ci/files/pirugegapidumikegilen.pdfIn 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://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_off0000d079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD079 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e88b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE88B 18560 bytes
SHA-256: 1f92899c09857d0894d3d1df866feb54e446150a822ff5b205b3fd290e7e6e21
font_02_sfnt_off000117aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117AA 10936 bytes
SHA-256: da2b13146c2bff3246b4bc66a9843721421ee21b9a4194fb380ff02f0c45cc69