Malicious PDF — malware analysis report

Static analysis result for SHA-256 23511bcc53cba7f6…

MALICIOUS

PDF

73.2 KB Created: 2021-02-12 12:32:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 09a31dcce29ebcc6eb52df36945f4160 SHA-1: bbdf5c7ae6cd743ae597a0a0a03b58cc118ab736 SHA-256: 23511bcc53cba7f6781bed7c43312b3a6a2cb98474eb22a51e1bd9152a3f56b6
244 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to disposable hosting or known redirector infrastructure, indicating a link farm designed to distribute malicious content. The primary link directs to 'yafferge.ru', a known malicious redirector. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://yafferge.ru/wix?keyword=coffee+shop+games+unblocked In PDF document text
    • https://cdn-cms.f-static.net/uploads/4462354/normal_60154ab14f92a.pdfIn PDF document text
    • https://cdn.sqhk.co/mudonisogub/FmhdgfY/splash_pad_near_me_now.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446263/normal_6023e901b377b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480423/normal_600b3ad02a25f.pdfIn PDF document text
    • https://bidijewufamidu.weebly.com/uploads/1/3/5/3/135325384/xesozed.pdfIn PDF document text
    • https://balusapox.weebly.com/uploads/1/3/1/3/131380564/70ca21e2046dbd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388040/normal_5fe78b2818634.pdfIn PDF document text
    • https://cdn.sqhk.co/gijesali/EoihvkW/push_em_all_mod_apk_hile.pdfIn PDF document text
    • https://cdn.sqhk.co/penutizufib/ifif5gj/tokizuxipur.pdfIn PDF document text
    • https://tudexabi.weebly.com/uploads/1/3/4/7/134770635/7069353.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492901/normal_601a0fd5cebe2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446490/normal_600eafb2a0b56.pdfIn PDF document text
    • https://walegizagoz.weebly.com/uploads/1/3/0/7/130775215/solaxesite-kusakirab.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445739/normal_5fc6831420ea5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421966/normal_5feaf88005402.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382430/normal_601b8351290d0.pdfIn PDF document text
    • https://dezijetide.weebly.com/uploads/1/3/4/8/134864221/wokejirowawi.pdfIn PDF document text
    • https://miboxijudowisu.weebly.com/uploads/1/3/4/4/134491333/5179588.pdfIn PDF document text
    • https://cdn.sqhk.co/kagurase/VBifEVq/download_naruto_x_boruto_ninja_voltage_pc.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
    • https://s3.amazonaws.com/jemazejodep/anesthesia_technician_resume.pdfIn PDF document text
    • https://s3.amazonaws.com/rizezobabub/online_work_timesheet.pdfIn PDF document text
    • https://s3.amazonaws.com/xapijifas/voraxokidepilakavufin.pdfIn PDF document text
    • https://s3.amazonaws.com/resixexi/2d_array_in_c_programming_examples.pdfIn PDF document text
    • https://s3.amazonaws.com/lazesej/fonidoterata.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d2d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2D8 5452 bytes
SHA-256: bdb2dde9d91599726fe2f31de85625fd551f4dc03f92f422c1473e994ce06686
font_01_sfnt_off0000e545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE545 10464 bytes
SHA-256: 8c03176d8b011e7544f8e78eeeefb6b4ffa31c7df80fb7a784efc54552644e40
font_02_sfnt_off00010919.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10919 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333