Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fd16e9a937507ab…

MALICIOUS

PDF

88.6 KB Created: 2021-09-18 09:38:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e9e1990569f54a1ad48edfb5ac1f82ef SHA-1: 21ae3987d44bfd39a86ea1c69256b3503d20602b SHA-256: 8fd16e9a937507ab080b6ec69138a79bb5781b2458a07ee4de1f89fc5f245070
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is identified as a link farm hosted on disposable domains, suggesting it's used to redirect users to potentially harmful sites. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest a phishing or malware distribution vector, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crewmak.ru/uplcv?utm_term=small+metal+plate+id+unturned PDF link annotation
    • https://nnt52.ru/userfiles/file/62378672443.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/mozulef.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210912_A71ED4D936377AB4.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/47255318269.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/lokomevatuzex.pdfIn PDF document text
    • http://classicalgardenfountains.com/uplds/file/48816055927.pdfIn PDF document text
    • https://cyklo-wellness-penzion-palice.cz/content/gopabuwem.pdfIn PDF document text
    • http://www.reeder.ee/files/filemanager/51470372927.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/larixixulowujexodug.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/91143076952.pdfIn PDF document text
    • https://corcreation.twbiz.me/data/fckeditor/files/20210904_140348.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/44787886991.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/82198832266.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/54658032052.pdfIn PDF document text
    • https://texasbordervolunteers.org/userfiles/file/samekijubazoderimela.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/21892282421.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/towexawiruxazejam.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/xawas.pdfIn PDF document text
    • http://kerama.altrodesign.eu/ckfinder/userfiles/files/befujuxaxemululojaxe.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/80f9ba9965780c76e6e8620e5141404c/lovoputesareferitenubala.pdfIn PDF document text
    • http://computerdoki.hu/user/file/zurovixuko.pdfIn PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/dorozonanazasoluvefuwafi.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/vaxaxexaketabiw.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_off0000f4dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DD 10440 bytes
SHA-256: 3c73ca52603901eee54745201aaa5bc8d916f2f0e370ec7055a09240a27b512c
font_01_sfnt_off00010c77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C77 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12489 17952 bytes
SHA-256: fe492ed83eec57ca07ebab4832169047ee7bde0dfd402db456407153d5be07f1