Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cc3244adcb325b9…

MALICIOUS

PDF

91.5 KB Created: 2021-09-09 17:21:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b03a88767afb2fb6215a27cd44e888ad SHA-1: 58d1dd592286df6eff585ba63b6765b156f74cf9 SHA-256: 8cc3244adcb325b99019b3588e63e08330490b002b7fa394e3ba684a1f9ad533
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are hosted on disposable or compromised platforms. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a deliberate attempt to create a link farm for malicious redirection. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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://queure.ru/uplcv?utm_term=chromium+64+bit+windows+10 PDF link annotation
    • http://vxclouds.com/userfiles/file/72612858416.pdfIn PDF document text
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/regimifopakefevo.pdfIn PDF document text
    • https://espiber.cl/images/uploadedimages/file/bixab.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/86096594333.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/lomubebu.pdfIn PDF document text
    • https://asiahealthcaredentalcentre.com/ckfinder/userfiles/files/xenigumo.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/10412923038.pdfIn PDF document text
    • https://tarsiman.ee/files/file/luwetu.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/manerewudawulenij.pdfIn PDF document text
    • https://shinko-tw.com/UserFiles/file/43442097799.pdfIn PDF document text
    • https://12shio1.com/contents/files/97510058409.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ab3a4284b---kepujekuwanaruza.pdfIn PDF document text
    • http://congluc.com/upload/files/7490873793.pdfIn PDF document text
    • https://studyhalltracker.com/files/file/mezosetetidepuluxises.pdfIn PDF document text
    • http://cartonwrappingmachine.com/userfiles/file/dalaxas.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/dedakabimeruwelemo.pdfIn PDF document text
    • http://vejwun.cz/images/sorofilix.pdfIn PDF document text
    • https://my-natural-style.net/upload/files/vufowedinedi.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/12319131704.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613450801ba21---35551080711.pdfIn PDF document text
    • http://adhunikjewellers.com/ckfinder/userfiles/files/jekumo.pdfIn PDF document text
    • https://foundationkuzmanov.com/files/27727100169.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359787aebf0---8334770199.pdfIn PDF document text
    • http://www.atsamuihaus.com/image/upload/File/toguno.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE768 10948 bytes
SHA-256: 893f80a21f98afc2adfb73233e3c0e308e91c176056c13bdcc908fc1a8dcec48
font_01_sfnt_off000100bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000118cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118CD 18996 bytes
SHA-256: 228bd62da46a29119f591bbde8de4662c0178c4542a24b5e316923c01457328b
font_03_sfnt_off0001493a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1493A 16384 bytes
SHA-256: d9fb07667674d0e8f83abc851466bbcf56df1163a84dd6cc70542b7b62470d92