Malicious PDF — malware analysis report

Static analysis result for SHA-256 6858bfb891abe4ba…

MALICIOUS

PDF

74.1 KB Created: 2021-09-05 09:49:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f084b0c383cd4aaac134a020457c5352 SHA-1: 3073549247f220d08b7bd202dcb369de32af8a97 SHA-256: 6858bfb891abe4ba06af00cc455a1a0507bcd8bc7a9de0aea8ed70e4a6bdefe4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, many of which point to compromised WordPress upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or redirect users to malicious sites. No scripts were extracted, but the overall structure and URL analysis point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://platcometals.com/images/file/24416446379.pdf In PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/62a9c06338b455cb1832baaabf841340/nezopilurinitexifilov.pdfIn PDF document text
    • http://becucci.it/userfiles/files/zuletakupa.pdfIn PDF document text
    • http://marymo.ru/uploads/files/12114040352.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/86a7bd9f85c526ac261ca854155d9084/sikuwagitawipuzorepad.pdfIn PDF document text
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/sufesidugazoxeboguxol.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1611ce5090769c---82351291600.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/aa3d726201b3478d99d9cb09339afa99/doxirepumetit.pdfIn PDF document text
    • http://slsnn.ru/content/files/74521239119.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210521012648188.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/567eb4e3de0ceb7f8d94c7573f73af55/45988401696.pdfIn PDF document text
    • http://varosom.hu/userfiles/files/muluzaxedojitig.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/juguluzipifajavazixotaf.pdfIn PDF document text
    • http://glavis.biz/userfiles/file/40393417370.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/16832498621.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/dekegopunuxegug.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6fdbbcb341---66873741505.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/adbedc8f528e37845f655adf6d8f0f9e/94811919036.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/qal6dlvvs0c66b6ahvhhgdsg2l/sazuxiraxuneje.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/42f06c8a0d415a71fa2fc9019264f1e0/95484359694.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f93daca037---kekajuwifisupoparoparus.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/venilutop.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/xiwifewizidugebi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=metabolismo+del+agua+en+el+cuerpo+humano+pdfPDF 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_off0000bd76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d58d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD58D 11300 bytes
SHA-256: b6b73a1687afa857fea11f109d4585cc1fa8f2813c20ca964a7273b4f7301796
font_02_sfnt_off0000ef70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF70 17240 bytes
SHA-256: 0752e03b58e5731b58e84e0694d8a8527a88a981476b5fe80d1d3c3d04027305