Malicious PDF — malware analysis report

Static analysis result for SHA-256 58bc844e4d6f864a…

MALICIOUS

PDF

77.7 KB Created: 2021-03-31 18:59:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f6b7a99d01a81a70ff8b207dcba658b6 SHA-1: 236e3056df8a9e45446093e3db3f2c06347b65bb SHA-256: 58bc844e4d6f864ac783ece86eaf6f823b7584cbbe1e3eb9c99c5ec35a0f949e
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are disguised as academic papers, indicating a link farm or SEO poisoning attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic confirm the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://resalured.ru/strik?utm_term=operations+management+13th+edition+mcgraw-hill+pdf
    • http://xapizokawe.iblogger.org/cours_espagnol.pdf
    • https://cdn.sqhk.co/pofaxiniraz/hipijhf/10738962706.pdf
    • https://cdn.sqhk.co/wopidevepip/jiejhih/bridge_constructor_portal_switch_physical.pdf
    • http://mobeditobaxul.scienceontheweb.net/umbilical_cord_prolapse.pdf
    • http://birebap.scienceontheweb.net/nidoligenumuxalefo.pdf
    • https://cdn.sqhk.co/sawibevas/2jggdif/frog_tape_medical.pdf
    • http://gokutep.22web.org/kuzaxomiwavamokuwepoxenir.pdf
    • http://mirumumavetifun.mypressonline.com/dagemik.pdf
    • https://cdn.sqhk.co/tumowara/ggjimjc/rogafug.pdf
    • http://gepopusoka.mypressonline.com/how_to_reboot_my_cox_cable_box.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/9ce94d14-02ea-448e-a94c-bcbe9e1238a0/arris_modem_cm820a_manual.pdf
    • https://uploads.strikinglycdn.com/files/f2835395-4668-4971-90cf-94caeb53723c/introductory_and_intermediate_algebra_for_college_students_fifth_edition.pdf
    • http://kolegigogar.rf.gd/blockchain_technology_and_applications_from_a_financial_perspective.pdf
    • https://uploads.strikinglycdn.com/files/9bc487a3-a896-493c-bf0c-d0e5ca32b64b/matofoseduxog.pdf
    • https://571cbd0a-ba82-408d-be6d-2df53a8fcfe5.filesusr.com/ugd/02af14_e509a5dad73a45aaa4a92203ccdca361.pdf?index=true
    • https://uploads.strikinglycdn.com/files/02cba30f-cd6b-4174-8e1c-05ac52da8885/45523384604.pdf
    • https://2a497570-3881-454f-aefc-229a18bbdf22.filesusr.com/ugd/83e24f_94f2565c9ca7474c976960e71713e29e.pdf?index=true
    • http://xokifenutotumu.epizy.com/chemical_bonding_worksheet_section_1.pdf
    • http://rezujadutifinom.rf.gd/aeroport_otopeni_informatii_bagaje.pdf
    • https://uploads.strikinglycdn.com/files/03443088-8bff-4d04-979b-6c2eba58e257/91171876788.pdf
    • https://d71fc03c-aea6-48f7-a990-8afffb22108d.filesusr.com/ugd/3de8a6_639d69ffbb6d41e29b3fcead145399b0.pdf?index=true
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef4d.bin
28f7311240abee20ca351f2d132635d3fab9b400788d19ee15b9022e1e1141ee		 pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4D 5936 bytes
font_01_sfnt_off00010374.bin
9ed63e1c9ef8f9cf2f7de3082003f2e503721219a8d94f46c5ffcb2021953198		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10374 11060 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.