Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c23af8d6130c32b…

MALICIOUS

PDF

72.5 KB Created: 2021-06-05 01:50:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: dbbc73a064334355633913de9102abb9 SHA-1: 84dee7e62827af90ca40dfc786b7da56a1010602 SHA-256: 4c23af8d6130c32b49017951308f90d5e460711ac5b6ce8c35fd10b8d1ab0ab4
146 Risk Score

Malware Insights

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

The PDF file contains heuristics indicating it is malformed and contains external URIs, specifically pointing to a URL that appears to be a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains text related to song downloads, reinforcing the lure. No scripts were extracted, but the presence of malformed streams and external links points to a phishing or malware distribution attempt.

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • 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://archism.ru/pbw?utm_term=ye+dil+kyu+toda+mp3+song+download+pagalworld+2017 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4479678/normal_5fddc1c93891c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406501/normal_5fc9d42c9bd35.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473415/normal_602e9b70a6ba5.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/e8d3cf5d-7018-4db2-8811-25d800c97d03/18700572922.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ba17abd-e0f9-45d8-85a9-4063e23779e9/splinter_cell_chaos_theory_bonus_missions.pdfIn PDF document text
    • http://zupelapowi.pbworks.com/w/file/fetch/144630132/lego_ninjago_season_14_episode_5_english_release_date.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ff81658b-5839-437d-8bee-d7438858ecdb/devaxagogevupivamop.pdfIn PDF document text
    • http://pesivop.pbworks.com/w/file/fetch/144633117/jazivisorodusamodatala.pdfIn PDF document text
    • http://wuwolufit.pbworks.com/w/file/fetch/144538824/74913040138.pdfIn PDF document text
    • http://joxupakager.pbworks.com/f/giwafubi.pdfIn PDF document text
    • http://xuwajesorewo.pbworks.com/w/file/fetch/144631473/fletcher_capstan_table_plans.pdfIn PDF document text
    • http://vulazojab.pbworks.com/f/25008863908.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f12f8439-3dce-494d-9d99-90cd593a463c/7852398062.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8efe0a63-bf3f-465f-a550-5f33fb3a173f/samsung_bd-h6500_software_update.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9e86cb81-63c8-4a1c-9c25-78f3202ef9c9/cyberpunk_2077_ps4_release_date_time.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3803d169-b7dc-4330-abad-e735184363d9/java_mvc_framework_tutorial.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1b05fcaf-574b-453d-8b68-8877b2aefd0c/al_quran_per_juz.pdfIn PDF document text
    • http://zuwofig.pbworks.com/w/file/fetch/144532974/kiwi_bird_fun_facts.pdfIn PDF document text
    • http://munonoraze.pbworks.com/w/file/fetch/144462519/far_cry_apk__obb_download_for_android.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dab8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB8 6068 bytes
SHA-256: 8622d9d5329247f1e348bb56b42320ac614dcea7e62fac48f8d4f34924348396
font_01_sfnt_off0000ef70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF70 10780 bytes
SHA-256: acded322c2d54816fe709eb294cf42ae0a85fe3a7443da7cffc5a1040a849e21