Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1bd1c91ca0bf28b…

MALICIOUS

PDF

71.9 KB Created: 2021-09-22 23:07:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bcb93392e069f2506e731dc586629204 SHA-1: 43541a9750435885ce7c093ad8c19275022ec5b9 SHA-256: f1bd1c91ca0bf28b073083b446ccb4ebacf36f8eba59b6bbc8ca77c638f90319
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files, many hosted on what appear to be compromised CMS uploads. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users to potentially malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://coretry.ru/uplcv?utm_term=lovecraft+books+pdf PDF link annotation
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/b8e960bb4e3d056843af8e193e9b2f6d/71271566196.pdfIn PDF document text
    • https://khonggiansangtao.com/platformecom/img/upload/file/96999386007.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/1442306152.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/pusovededusupusaji.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/fijijetibidikapad.pdfIn PDF document text
    • http://bbbo.handyfriendship.com/upload/files/wejefegulitugixokasobu.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/jenovimewavin.pdfIn PDF document text
    • http://daehnfeldt.com/userfiles/file/dosinuwipuxerefixuf.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/92142175612.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/161319bc7804a1---61010034699.pdfIn PDF document text
    • https://www.bramfordgc.co.uk/ckfinder/userfiles/files/30343560200.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/sotil.pdfIn PDF document text
    • http://khyljg.com/uploadfiles/files/tanudujodowubowe.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/92878572224.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/45049487994.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/diwawaporupebuzo.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16130218e9796f---tumiwepetikoj.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/90561949997.pdfIn PDF document text
    • http://lor-rostov.su/userfiles/files/19736170269.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/8778187128.pdfIn PDF document text
    • http://traviet36.com/upload/files/wabaxonopeselivaxikeru.pdfIn PDF document text
    • https://attack.lt/images/files/jisisetaje.pdfIn PDF document text
    • http://gazduire-domeniu.com/UserFiles/file/dolovaref.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_off0000bafd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAFD 10628 bytes
SHA-256: 97a7aa414fc0f472f035034e63a5a6a1c5cceda38cfc40c1fa65fda0c94e5c91
font_01_sfnt_off0000d343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD343 15328 bytes
SHA-256: de97fc8eaa01b6dfa6beb388d3dc489840e835ab69cca12b35bdfba592ef927d
font_02_sfnt_off0000fa30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1