Malicious PDF — malware analysis report

Static analysis result for SHA-256 824a5a86594136e0…

MALICIOUS

PDF

74.8 KB Created: 2021-09-19 08:43:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cd10d2173941456cd4722aa23980ebdb SHA-1: 5f4637fd182d8b02081416da09144ea6f36875f4 SHA-256: 824a5a86594136e0ea2a94ab8acce886ea03b28229269ad4191b98cbf8dde40d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to unknown or potentially compromised domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kunmobile.vn/files/uploaded/20210913/file/47519856774.pdf In PDF document text
    • http://szentdorottyapatika.hu/files/wawetet.pdfIn PDF document text
    • http://pinzimoniofiumicino.eu/userfiles/files/towarimulivujenakurusimu.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/zafumazuda.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/nelanejuroderujero.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021090210361848.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/11255315468.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140846bc252b---64934583433.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/52050494673.pdfIn PDF document text
    • http://acevina.com/webroot/img/files/wigedezebita.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/pmvtc1ci9sj851cfilt9dlt296/17946255500.pdfIn PDF document text
    • https://chennothinterios.com/uploads/file/joruv.pdfIn PDF document text
    • https://vleek.com/uploads/files/senesolaz.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613048a85bf4d---92037390193.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/filuwerafetided.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/budoj.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/susibosojifune.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/nasolebitekofa.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/83096220737.pdfIn PDF document text
    • http://aaronandanthony.com/userfiles/files/nukijonirubila.pdfIn PDF document text
    • http://szm.hu/userfiles/file/72756469807.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/gugumifaxuje.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/80124119321.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=capricorn+customer+application+apkPDF 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_off0000c036.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC036 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD848 16892 bytes
SHA-256: 69b6e65a8d9d5fb8dc9a992ef6a8cab0b7e9f4307ec1e8fb1ac9600f5264bfd8
font_02_sfnt_off0001049c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1049C 10756 bytes
SHA-256: ac3ea387e1804433e160413602c7ee03658fb8bd71c059fd61d06967c0ea1c98