Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3b85cdbaec19040…

MALICIOUS

PDF

82.2 KB Created: 2021-03-24 11:53:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: c53294738652ff2e2c8e911b694e4766 SHA-1: 16b74e99b51a7e333568636e6ee447b2a9f39727 SHA-256: a3b85cdbaec190407acef002d5b6894388c3957242a9f87773551857c634a55f
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an urgency-based lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://lozipotod.ru/strik?utm_term=how+to+subscribe+on+twitch+app+with+amazon+prime PDF link annotation
    • https://cdn.sqhk.co/xosuridasago/Mjfhbsg/edge_lighting_not_working_note_10.pdfIn PDF document text
    • https://cdn.sqhk.co/denepepunuja/aiaicie/tugozufusotexabuwado.pdfIn PDF document text
    • https://cdn.sqhk.co/fujalapevame/fahaAhc/bubble_letters_font_dafont.pdfIn PDF document text
    • https://cdn.sqhk.co/pelonulu/jbjcDif/fivuwi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416787/normal_600fee5955efb.pdfIn PDF document text
    • http://nuwiratuzitezep.22web.org/bulksms_for_android_apk.pdfIn PDF document text
    • http://kuvelopomegemes.iblogger.org/transtorno_da_ansiedade_generalizada.pdfIn PDF document text
    • http://bumalutaf.iblogger.org/casadio_dieci_a1.pdfIn PDF document text
    • http://raweloridewuwo.22web.org/romeo_and_juliet_vocabulary_act_1_worksheet.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490920/normal_604cd23e38684.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365594/normal_5fd2339b5f350.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://japivolenalu.epizy.com/zosedanug.pdfIn PDF document text
    • https://77da94c0-0f0a-445b-87af-e489a0b5ef66.filesusr.com/ugd/db1da1_8933a4ced1344b1a984a91e63d33a80d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/guwutivupudutu/62923776857.pdfIn PDF document text
    • https://c06d174a-caca-4ab2-b5a0-4525cd3135d4.filesusr.com/ugd/856cea_bd6f461fcde84eb9845dea5ab80fb27e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tamobalasu/3867206578.pdfIn PDF document text
    • https://s3.amazonaws.com/zagubip/33008631187.pdfIn PDF document text
    • http://bexatati.epizy.com/meme_generator_free_apk_uptodown.pdfIn PDF document text
    • https://s3.amazonaws.com/xofalepelala/escape_from_alcatraz_quiz_answers.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f34f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34F 4112 bytes
SHA-256: dd6547652491c0798a29f7b4f1e19ff63efe3f1b40205d5e1cee76f16ff0cae7
font_01_sfnt_off000101f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F1 5384 bytes
SHA-256: 0cbb1c031fef128436ef50170349d65b185eee6d2b77b12e64203d5237de520e
font_02_sfnt_off0001142c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1142C 11304 bytes
SHA-256: 43071a3cddba770b0fc42725cb5b9119d5164f1677645edf4e05ee752137d11f