Malicious PDF — malware analysis report

Static analysis result for SHA-256 4877cb4db16075d3…

MALICIOUS

PDF

108.4 KB Created: 2021-03-22 16:52:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 324f8ddab42a1d4120d1c35a30f23cda SHA-1: 2658cd400b1b4a6ddcd7fc9a253695d88737e32f SHA-256: 4877cb4db16075d3a969e58cfb7334ba9e32245265b864e9a0a1645f21a1b7f5
244 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic identifying it as a malicious redirector and a link farm. The primary URL, https://dafemum.ru/award?keyword=acuerdo+de+paz+de+la+habana+pdf, is flagged as malicious. The document body is heavily obfuscated, but the presence of embedded links and the heuristic firings strongly suggest a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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=acuerdo+de+paz+de+la+habana+pdf In PDF document text
    • https://cdn.sqhk.co/guwezasov/eOhv2FO/68519882573.pdfIn PDF document text
    • http://bimamoked.iblogger.org/dream_interpretation_snake_bite_left_foot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427544/normal_602c76da8e7df.pdfIn PDF document text
    • https://cdn.sqhk.co/fetuxudo/bNhihcv/tyre_tread_depth_check_gauge.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369146/normal_6035526ee7861.pdfIn PDF document text
    • http://nusamovepi.22web.org/arm_cortex_r52_technical_reference_manual.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410965/normal_5fea42a9238ce.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454973/normal_5fd1e28a423a7.pdfIn PDF document text
    • https://cdn.sqhk.co/gidulikegel/dgjUijY/igt_online_slots_free_play.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470409/normal_6010f20ef20f6.pdfIn PDF document text
    • http://bimelar.22web.org/dojegegexapil.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4455403/normal_5fdfcd3ab01b6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414152/normal_5fd06c112c4de.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nufurezoguboli.epizy.com/66580247284.pdfIn PDF document text
    • https://c78267de-509c-4cb0-9394-6b21b7876e04.filesusr.com/ugd/290ce3_df334079321445799dab28aaa8d6ae6e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d1ed9a8-c708-4b44-815c-e90751da6709/how_to_connect_samsung_scx-3405fw_printer_to_wifi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90974c3d-66a1-432a-8ffa-99ce7c6dd9dd/ielts_academic_writing_task_2_samples_band_9_download.pdfIn PDF document text
    • https://6f465708-eb37-4ee2-8658-ebeec6cd93ea.filesusr.com/ugd/4bb103_ee72bdb0901d4e4a8e28629c9f9f3b3d.pdf?index=trueIn PDF document text
    • http://labazesunug.epizy.com/autodesk_dwf_design_review_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/47837fb2-58b5-42c1-951b-b490dbb2d50b/53533234813.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016b1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B1F 5244 bytes
SHA-256: dca55c116ad3e8b52c42d125efe17fd627f44f99f0e48e75dd117b7a8f3c64ea
font_01_sfnt_off00017cf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17CF3 11884 bytes
SHA-256: b04142c4b0a7b0740300e92781c01cf1901e32fc98dd96c13db64dfba8453200