Malicious PDF — malware analysis report

Static analysis result for SHA-256 38881fccc8c5d215…

MALICIOUS

PDF

89.3 KB Created: 2021-03-22 21:29:33 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: dd9e285e2dfd6b87df05dd411f6d15e3 SHA-1: 4e6fcac08e0d1979abacdf0d26c8a54fdd486047 SHA-256: 38881fccc8c5d215bfac4037c52fc7005e2530002922199c1ed9d51df1ba50be
134 Risk Score

Malware Insights

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

The PDF file contains multiple external URLs, including one that appears to be a download link for an 'english typing book'. Heuristics indicate the PDF is a link farm on disposable hosting and has been flagged by a machine learning classifier and ClamAV as malicious. The presence of external URIs and the overall structure suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://resalured.ru/award?keyword=english+typing+book+pdf+file+download PDF link annotation
    • https://cdn.sqhk.co/kekelivig/c9hjhaI/legit_online_shopping_sites_usa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389824/normal_6057aac0dcb58.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450516/normal_605063be0d90f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418365/normal_60517abf0c206.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420756/normal_6041ab420b941.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486535/normal_602786ca32e54.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369185/normal_60323f04a7e8e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490722/normal_6015a9963a726.pdfIn PDF document text
    • https://cdn.sqhk.co/jagapifa/yjjehdN/wedding_haircut_near_me_now.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4496153/normal_5ff845c46d82c.pdfIn PDF document text
    • https://cdn.sqhk.co/sikereri/AHScijp/tusajibuvexi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480182/normal_603e09c7e56dc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413573/normal_601ff83b81da3.pdfIn PDF document text
    • https://cdn.sqhk.co/vetedaxuzele/jgdjfji/coast_to_coast_by_westlife.pdfIn PDF document text
    • https://cdn.sqhk.co/dudumadopole/bigPjaV/vagibugumafatosotezujoro.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://sokevojufepizi.rf.gd/samid.pdfIn PDF document text
    • http://vaxalisuj.rf.gd/sat_exam_books_free.pdfIn PDF document text
    • http://disiroto.epizy.com/o_level_chemistry_2019_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b700c3e-ab0f-4374-9c05-3a7883dd07a1/suzuki_violin_book_1_piano.pdfIn PDF document text
    • http://fekerudosepu.rf.gd/bollywood_hd_movies_300mb_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c521e1f-6663-4430-9841-32be07010de8/krik_krak_sparknotes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/45d217b5-ff62-4439-bea0-02d7e498bbce/majarugegetewakijuzamaxet.pdfIn PDF document text
    • http://fopagozijudiri.epizy.com/xotapifeworugapigokufubin.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_off000107c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C4 5564 bytes
SHA-256: e63d60d359a83081a06de9247d780576c1ba0f25ed7995d161ad6b3ca786f57c
font_01_sfnt_off00011acf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ACF 11960 bytes
SHA-256: dc3a4c44a39d3cf6dcab1a654a9c5714430ffd52afcc59fb4823845cf93d9aa2
font_02_sfnt_off00014375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14375 6032 bytes
SHA-256: 83d74faa01938ecf29686996833405f78a266f0324a83d8dca9791c8e0a3af36