Malicious PDF — malware analysis report

Static analysis result for SHA-256 22d13a5c4e8a3dd7…

MALICIOUS

PDF

88.5 KB Created: 2021-03-29 08:22:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: db587b77a9fd079c30a2368c4ec89a8b SHA-1: dcdd3a5376bdef784f7cd40e92208ee135ead0e5 SHA-256: 22d13a5c4e8a3dd7535b5ae7c32f199407d4a43f95e9ce0bda074eeef3fac8dc
244 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of embedded links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The primary malicious URL identified is https://crophysi.ru/wix?keyword=text+features+matching+worksheet+pdf, which is flagged as a malicious redirector.

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://crophysi.ru/wix?keyword=text+features+matching+worksheet+pdf In PDF document text
    • https://suzefajadovu.weebly.com/uploads/1/3/4/5/134592553/ditow_runuwen_xokubijez.pdfIn PDF document text
    • https://cdn.sqhk.co/mikevoponage/1NibNnN/57521860783.pdfIn PDF document text
    • https://cdn.sqhk.co/wogokodu/dhgibwQ/baby_grows_up_doll.pdfIn PDF document text
    • https://tupisefam.weebly.com/uploads/1/3/1/3/131383837/cfcd620df.pdfIn PDF document text
    • https://cdn.sqhk.co/xizefonuma/gjjeQhg/zipuw.pdfIn PDF document text
    • https://zakiguranul.weebly.com/uploads/1/3/4/4/134480990/xaluwegux_sabirapavalova_xoganaku_padosigisob.pdfIn PDF document text
    • https://cdn.sqhk.co/dadirowuj/hLHnNLB/jokovofabaterenotapafesu.pdfIn PDF document text
    • https://cdn.sqhk.co/navimoxa/hX6idHh/90367659308.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ef4b221f-cfb4-47e8-bf1d-3b5092770df7.filesusr.com/ugd/4948da_f6d0395be7a14ababfc004240b8569ec.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tuzamada/27796007228.pdfIn PDF document text
    • https://s3.amazonaws.com/liwara/bekirivo.pdfIn PDF document text
    • https://ef2e072a-e8a2-4438-804d-cc750be2e2f6.filesusr.com/ugd/6a22cb_d509ed7fbe9141a1987561ffac42a057.pdf?index=trueIn PDF document text
    • https://8a5a474a-a671-4857-921d-d1df0ee72544.filesusr.com/ugd/523716_23ecf820176a40e9846cbee140dbfee7.pdf?index=trueIn PDF document text
    • https://5984e891-aecd-43e6-866f-efdb297c9c35.filesusr.com/ugd/403565_29cc4ba019304f50ad5b03e9af78a314.pdf?index=trueIn PDF document text
    • https://8eeb1f0a-0cdd-4c66-98a4-83777b49fb54.filesusr.com/ugd/64f9d2_bd8134a3838e45a7abc328d1ae6be462.pdf?index=trueIn PDF document text
    • https://46a1ac71-481d-4a85-b709-d40f3a189542.filesusr.com/ugd/143c98_61c2d26b1acb4c6fa00767dbf257e73b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xujitezu/bass_guitar_theory.pdfIn PDF document text
    • https://dba0ca6b-c979-46b3-87c9-041648dee063.filesusr.com/ugd/6f58fb_f3304067a4ff4ef9a3b7aa6d58c7e3aa.pdf?index=trueIn PDF document text
    • https://6b9ff03a-ef48-417a-a14c-919df0f903d0.filesusr.com/ugd/f459ea_b20475ebbdae479b9f7ea88a6748db55.pdf?index=trueIn PDF document text
    • https://b354d503-40d1-4c97-84b4-bc0b16c12f35.filesusr.com/ugd/8c7d07_92c5e53f40434746ba2c61b5ac161c44.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_off0001199c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1199C 5708 bytes
SHA-256: f64042a557964bd7daf9a5439207ac452dcd450c5d3bca9c7e237fd734f9f287
font_01_sfnt_off00012cfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CFB 11724 bytes
SHA-256: facdc667eaa6664ce5f416f64839915611339f513448dca4b3f2dd1efebdffc4