Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9de1c858ab911f2…

MALICIOUS

PDF

73.8 KB Created: 2021-03-23 14:42:00 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 958e9ef2df05da805a595eaf72f2d1c7 SHA-1: f8991dc977c2025418ffd86fe421dc8e49031475 SHA-256: c9de1c858ab911f2896c1212a2a97082a95b07f878c932f6ed85a1a55f5176c3
244 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to disposable hosting or redirector infrastructure, indicating a link farm designed for malicious purposes. One critical heuristic identified a link to known malicious redirector infrastructure at 'https://dafemum.ru/strik?utm_term=life+life+insurance+plans'. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the structure suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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/strik?utm_term=life+life+insurance+plans In PDF document text
    • https://gugibutuxu.weebly.com/uploads/1/3/2/8/132814167/kinaxefaparadu-gisogex-fotejake.pdfIn PDF document text
    • https://luzenesezenobo.weebly.com/uploads/1/3/5/3/135307250/mefufinu-lapinexu-temimutowuje.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450440/normal_60555e9d10411.pdfIn PDF document text
    • https://kiwitelovig.weebly.com/uploads/1/3/4/3/134358902/3ee33.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449622/normal_602c83956b692.pdfIn PDF document text
    • https://cdn.sqhk.co/niserutom/HhgnYii/slot_car_racing_sets_near_me.pdfIn PDF document text
    • https://cdn.sqhk.co/wanowofimaz/hxaghbq/wormax._io_hack_tampermonkey.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463287/normal_6050d20aa9fa7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484364/normal_5ff71ac46b2cc.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://4bbf79d8-97e4-42de-9a75-948158c354f0.filesusr.com/ugd/52f5d3_ddc26dec1f3a48fb8e3bcebc177ab07f.pdf?index=trueIn PDF document text
    • https://f7cac2f2-528f-490f-9bef-cb2448a877de.filesusr.com/ugd/529ba0_73fd26c492a649978e43cc72305b9e68.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kavalukato/sifipebipegerivox.pdfIn PDF document text
    • https://d05b2b94-0af3-401c-a6ef-75d00d0b58ae.filesusr.com/ugd/3bca44_f707d7caa38f4ee28aba242d94d89f86.pdf?index=trueIn PDF document text
    • https://73e25548-3913-4bbb-aa69-a1b25f69568d.filesusr.com/ugd/cece23_faf920f235ea44d79fef215ba4ddf891.pdf?index=trueIn PDF document text
    • https://64f1e6a9-4530-4009-9f9b-67b91dd69f79.filesusr.com/ugd/76b6de_821fc5811102484082cebb3ab6ed386c.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jitimesolagun/crocodile_tears_rs3_quest_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/pevarijidasalop/binkw32._dll_for_windows_7_32_bit.pdfIn PDF document text
    • https://98771922-91e4-4673-aa0d-7794f4435593.filesusr.com/ugd/b6aaa0_d3cd7685b9b4407d94bf329d008ea50a.pdf?index=trueIn PDF document text
    • https://32cf4326-ba62-484c-a3ca-05d02c2dd2e5.filesusr.com/ugd/0b46e6_1e9b3a4fc8dc42139949000e2870cb3b.pdf?index=trueIn 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_off0000e359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE359 4948 bytes
SHA-256: 4ff0256464a5c02ddf6560db7e305642471aa4f46fcc08176cba09e7c0c16a7b
font_01_sfnt_off0000f445.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF445 10512 bytes
SHA-256: aa1acac1e1db0cead1daa255e44240c4eec084340f2c330bf6d5c02cb9469fa3