Malicious PDF — malware analysis report

Static analysis result for SHA-256 40c54ff90fb421fd…

MALICIOUS

PDF

81.1 KB Created: 2021-06-11 13:28:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: b322d1d4ca72a71611e4108706c6056c SHA-1: aab3d7986bd46f630f2f73699eaa3f41269e50c4 SHA-256: 40c54ff90fb421fdc75737c98d5f14661a8a5cea6c987aaaa3f88e54fc5eda73
246 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many of which point to disposable hosting services, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically for credential phishing, as indicated by the 'SE_BRAND_CREDENTIAL_PHISH' heuristic. The embedded URLs likely serve as lures to redirect users to phishing sites.

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.
  • Brand-impersonation credential phishing lure critical SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: action link to abused redirector https://negijozizur.weebly.com/uploads/1/3/0/7/130775009/801334.pdf.
  • 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://queure.ru/pbw?utm_term=samsung+bypass+google+verify+apk+2020 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4393188/normal_60ba81b3b7419.pdfIn PDF document text
    • https://negijozizur.weebly.com/uploads/1/3/0/7/130775009/801334.pdfIn PDF document text
    • https://wuzubetimu.weebly.com/uploads/1/3/4/2/134266391/1645307.pdfIn PDF document text
    • https://wiwotejezewol.weebly.com/uploads/1/3/4/6/134691264/zesol.pdfIn PDF document text
    • https://ruzabipisoxo.weebly.com/uploads/1/3/4/5/134528447/lubimopomegom-fejewosejoxil.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490736/normal_606b33518f7ce.pdfIn PDF document text
    • https://donabetolemi.weebly.com/uploads/1/3/1/6/131637402/4375336.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481990/normal_600d7d68d4189.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wikitaxif.pbworks.com/w/file/fetch/144580347/mibomexonojaro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6089bc9-6dec-402b-841a-34c03b7e2876/how_to_look_up_mutual_fund_ticker_symbols.pdfIn PDF document text
    • http://jajafad.pbworks.com/w/file/fetch/144427971/diary_of_a_wimpy_kid_the_last_straw_pages.pdfIn PDF document text
    • http://fijinatuzut.pbworks.com/w/file/fetch/144568134/zemekotuvelezepujixisod.pdfIn PDF document text
    • http://kokoxudalux.pbworks.com/w/file/fetch/144427449/how_to_make_gelatin_sheets_from_powder.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/878ca462-1a1b-4223-b380-4e6491e5e246/43726514821.pdfIn PDF document text
    • http://mujefapufefi.pbworks.com/f/70580890132.pdfIn PDF document text
    • http://wiwedano.pbworks.com/w/file/fetch/144427869/anthologie_les_fleurs_du_mal_thme.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0B 5964 bytes
SHA-256: b79732538bb9a8067f78aaafb11bbcce5db8dffe7e026820a360defb60eea9b2
font_01_sfnt_off0000ef4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4F 19456 bytes
SHA-256: 8ef3361e482f0168280a937b7531327176f895ec908ef6921f5a587189273b73
font_02_sfnt_off00011dbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DBB 17464 bytes
SHA-256: 17af942796bbc741f411ff56685ea93905ec6c2180c9a9b83c7881d65f2a0c55