Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb389791a773c546…

MALICIOUS

PDF

73.6 KB Created: 2021-03-17 21:25:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 957c5e69e4732c4d48be4f3e55f60439 SHA-1: d226907528bf5bcceba1ad134a5148e9e6b69c75 SHA-256: cb389791a773c54667f8dbc472ab28476aa3cdb6b7b79fe8601fd8d61104224e
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to potentially malicious content. The document body, though heavily obfuscated, appears to be a lure related to 'class ab power amplifier theory pdf'. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • 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/award?keyword=class+ab+power+amplifier+theory+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4459164/normal_602a370b1b0c4.pdfIn PDF document text
    • https://cdn.sqhk.co/fagaxirupunu/1ieRpgh/14309164055.pdfIn PDF document text
    • https://cdn.sqhk.co/pepupiribojo/jOaaCjf/best_radio_stations_italy.pdfIn PDF document text
    • https://cdn.sqhk.co/lopijikuvi/dBjgYSR/1082393764.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388827/normal_6017cfab37e35.pdfIn PDF document text
    • http://bidizujimon.getenjoyment.net/effective_communication_consists_of.pdfIn PDF document text
    • https://cdn.sqhk.co/merivexasug/gcUidjc/phoenix_weather_december_celsius.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418167/normal_605067fdaafcc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376098/normal_5fec44fb7db47.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449183/normal_5ff61687b4540.pdfIn PDF document text
    • https://cdn.sqhk.co/mukujoripu/iIVfMbA/rune_pickaxe_osrs_shop.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://newepizudef.atwebpages.com/wawizuxazevaxukiralubeku.pdfIn PDF document text
    • https://c6de0af5-2a4c-46da-924c-839bccb102c6.filesusr.com/ugd/5f1f0f_2088ce34a090487fb8daf28a5af4ad0e.pdf?index=trueIn PDF document text
    • https://22e365c6-0853-42e1-82f8-83473bf9c0bf.filesusr.com/ugd/217d68_6476b477f70744408bd8f4cc7e89c8b1.pdf?index=trueIn PDF document text
    • https://b0c090b1-cb02-46d8-8a69-3fb9d82636b6.filesusr.com/ugd/4dbf3f_24911fee3d7344af88fe897ed55cfb0f.pdf?index=trueIn PDF document text
    • https://ce3a146a-d504-4efb-981c-4593fb85d965.filesusr.com/ugd/5b5da7_bf1d80ebc59147e08cc6c44dcae08969.pdf?index=trueIn PDF document text
    • http://pikubub.onlinewebshop.net/aircraft_maintenance_technician_jobs_canada.pdfIn PDF document text
    • https://8d90b851-447f-4cfc-ac95-1e867b71b983.filesusr.com/ugd/b371d9_ffd7605b3b62453ca6c8325d598b0075.pdf?index=trueIn PDF document text
    • http://kepofif.onlinewebshop.net/18257003457.pdfIn PDF document text
    • https://9a1eab6f-da2d-4a41-99bb-18a59f11b130.filesusr.com/ugd/c2b690_59f459f71d594e1aaf0ebf981e608b61.pdf?index=trueIn PDF document text
    • https://d54d55f4-8004-4613-9f19-7b96cbed0ae7.filesusr.com/ugd/ce4b32_41a8ec3da0c94f6fae554039fdb768b7.pdf?index=trueIn 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_off0000e3a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A6 5520 bytes
SHA-256: d42da7e06189f6e327c992a3f78f9e472b08fb4af95f0774be21e19859d09981
font_01_sfnt_off0000f648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF648 10300 bytes
SHA-256: 55457bf58eb7acfca33d0246ce3eefd10e22043db0da31c04f2926c06352ac30