Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4bf2b58f5ca3b98…

MALICIOUS

PDF

83.2 KB Created: 2021-03-23 02:30:39 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 2161a85a199f6c623775e1d124b3c624 SHA-1: 23810208235147615c5004c8592d7967bd591dc0 SHA-256: d4bf2b58f5ca3b98ba9a17521ee7b0af92a61f2f59bb3bfedf56cb81f8068519
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple embedded URLs, with at least one pointing to known malicious redirector infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to a story PDF, aiming to trick users into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/award?keyword=aparichita+rabindranath+tagore+story+pdf In PDF document text
    • https://cdn.sqhk.co/susojitigi/chiN6ge/4100905407.pdfIn PDF document text
    • https://cdn.sqhk.co/tutogalubete/eihU3jf/360_antivirus_for_android_phone_free.pdfIn PDF document text
    • http://portkamesto.site/juxipewufrymjn.pdfIn PDF document text
    • http://justamorem.com/4821397088uukq.pdfIn PDF document text
    • https://cdn.sqhk.co/burajugi/gvzjgIH/the_hangover_part_4_tamil_dubbed.pdfIn PDF document text
    • http://madamzero.com/kodafuruxepogelirixkqzq7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459324/normal_603039c6ef828.pdfIn PDF document text
    • https://cdn.sqhk.co/kulobibab/vgduS06/18258429058.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366407/normal_5fe4bbf137fd0.pdfIn PDF document text
    • http://vatidenow.medianewsonline.com/albertsons_grocery_store_job_application.pdfIn PDF document text
    • http://kavelizopepi.mywebcommunity.org/typhoid_fever_journal_2020.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385636/normal_5ffeb30fd2bc7.pdfIn PDF document text
    • http://naturfresh.fun/organisational_behaviour_book_for_bbaatnz6.pdfIn PDF document text
    • http://buloshnaya.site/xupugujebn4wg7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://vubuzixefixa.onlinewebshop.net/52390450069.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6dcd1296-8256-4f34-9362-14fcfa31a7f9/dikixapimelovavafunudev.pdfIn PDF document text
    • http://xevijojikutep.onlinewebshop.net/amor_a_dois_andrei_moreira.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/52b01a11-237b-4ee6-9b87-a063c7468122/after_we_fell_movie_shooting.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9fc3737e-a1ea-467e-b1e3-aff3cd0bb76b/dry_density_of_cement_in_kg_m3.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://scripts.sil.org/OFLIn 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_off0000e391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE391 5404 bytes
SHA-256: 92789141ce2792fdf96c0c2f861da50387bd91309b4aa1a218869cb8db6c2d78
font_01_sfnt_off0000f5df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DF 10436 bytes
SHA-256: d3fbcb3833db88b5100034a9f86c50f0dd47547c15e8a9062681e8d0249479b9
font_02_sfnt_off000119e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119E0 16092 bytes
SHA-256: ea75db71c9df7250347a03039f742fcd189f5fc3f08964e696816fa8b5227073
font_03_sfnt_off00012ea8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EA8 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361