Malicious PDF — malware analysis report

Static analysis result for SHA-256 753b910b1b993be6…

MALICIOUS

PDF

75.1 KB Created: 2021-03-26 07:13:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 963c010105ec5619a899baa809b7e4e9 SHA-1: aed88cb5f905c1dbdb0d58cf0afcbc67cdc556c6 SHA-256: 753b910b1b993be60f5386d18c0a84eb4ff12814439ae437f843fe0b132d41fc
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 search results or file downloads, indicating a link farm or phishing attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to malicious websites or download further payloads. No scripts were extracted, but the PDF structure itself is indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jumiwimov.ru/award?keyword=cayley+hamilton+theorem+proof+pdf
    • https://cdn.sqhk.co/folamudoj/gcJjf06/lead_school_parent_app_free_download.pdf
    • https://cdn.sqhk.co/xesofosirija/japjdhC/galatea_addictive_stories_mod_apk.pdf
    • http://zapazereti.22web.org/14640803383.pdf
    • http://googsnat.space/rufujuri7ympf.pdf
    • https://cdn.sqhk.co/xifobariw/jjm9Pif/snapchat_icon_black_aesthetic.pdf
    • https://cdn.sqhk.co/soxesemu/hiOgchc/91288514790.pdf
    • https://cdn-cms.f-static.net/uploads/4407998/normal_605d329237ac8.pdf
    • https://cdn.sqhk.co/kivipemo/CFgdiND/wobokosomapodotiw.pdf
    • https://cdn-cms.f-static.net/uploads/4476436/normal_60272ded9740a.pdf
    • https://cdn.sqhk.co/wakewafo/cgdgcig/lexia_reading_core_5_level_13.pdf
    • https://sozogamawi.weebly.com/uploads/1/3/1/6/131636736/7e716516.pdf
    • https://samaruwopag.weebly.com/uploads/1/3/0/7/130738554/sadazikoluzow_fikatoporelow.pdf
    • http://matras-24.ru/bawafodutujfj2l5.pdf
    • http://fuxewofuwikafu.iblogger.org/agenda_web_present_continuous_exercises.pdf
    • http://good-production17.site/ridgeway_registered_serial_number8lmie.pdf
    • https://cdn.sqhk.co/nuxazagugura/jhgejjl/79713625108.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://natizat.epizy.com/kalender_2020_lengkap.pdf
    • 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_off0000ea1c.bin
7da8667c432bf15dfa2c2bc965f7f6e6e0e3f9cb9de732bfc93890e30b058b95
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA1C 5112 bytes
font_01_sfnt_off0000fb5a.bin
472bcb2844d148a7e6880c10e9728397ec239040ebe67489159b3f28ba7683de
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5A 10824 bytes