Malicious PDF — malware analysis report

Static analysis result for SHA-256 73db7545dd203fb5…

MALICIOUS

PDF

76.5 KB Created: 2021-04-26 12:14:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd6be6485563f67b057c78f815597087 SHA-1: e3f75810199cceeeffa1ae7e9dde8e95bb57c1e0 SHA-256: 73db7545dd203fb52746d870c32911f4eb5c2380bef1d88b24be254af2a1f4e9
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to PDF files hosted on various domains and CDNs, suggesting a link farm or distribution network. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically phishing. While no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of techniques used to redirect users to malicious sites, likely for further payload delivery or credential harvesting.

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-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://golowaki.ru/strik?utm_term=the+wave+book+summary+chapters
    • https://cdn.sqhk.co/pabilere/7Dhemhf/3316743602.pdf
    • http://nout-prodat.site/dodigipozibgaleh.pdf
    • https://wivixovipi.weebly.com/uploads/1/3/4/4/134442696/889dce508af.pdf
    • https://cdn.sqhk.co/topefebi/hegChb5/baby_centre_pregnancy_week_by_week.pdf
    • https://cdn.sqhk.co/naxibibu/gdc0Psi/sky_warrior_theater.pdf
    • http://mastericy-chistoty.ru/subject_verb_agreement_practice_answersub2b2.pdf
    • https://cdn.sqhk.co/metexemoraga/569skic/55733580976.pdf
    • https://cdn.sqhk.co/kulobuwaxegu/aR8heib/synchrony_car_care_pay_by_phone.pdf
    • https://cdn.sqhk.co/wuvotalek/Kjhjlqn/valewu.pdf
    • http://filfex.ru/32233732388yvu9a.pdf
    • https://cdn.sqhk.co/letowajaf/Vljaie4/pictowords_level_7_answers.pdf
    • https://bogizironafek.weebly.com/uploads/1/3/1/4/131406395/7417604.pdf
    • https://cdn.sqhk.co/parabeset/BhcYhei/doctor_robot_emergency_animal_rescue_robot_games.pdf
    • http://swiss-gear.shop/549491302797v8z.pdf
    • http://subfamjtii.site/fasudelaxadodenuf9p7qq.pdf
    • https://cdn.sqhk.co/nadipozow/bjdQUXo/christian_bale_song.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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_off0000ec5a.bin
72253a6606f9c9b92e56743cf5375f9fcdf5b57d6db040196dceff6d07cb47e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5A 5548 bytes
font_01_sfnt_off0000ff2b.bin
9aecdb9180ecdb057ee6d4561934018d2386f18795677a7aec8f3d3dea30e5f3
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF2B 11288 bytes