Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef08d7ac03be55b6…

MALICIOUS

PDF

66.9 KB Created: 2021-06-10 11:24:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 2d195d400767aba32dbc4989f849f618 SHA-1: a8a44c89f1d0ea7e652ef43a1da19394c3725ace SHA-256: ef08d7ac03be55b6ea7dfee25edf54f1f45d8dc2e66cca7c46bf5e316093937c
134 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan payload. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is part of a link farm designed to host malicious content, with a specific URL pointing to a potential download. The presence of embedded URLs and the overall structure point towards a phishing attempt to trick users into downloading further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://crewmak.ru/pbw?utm_term=adjectives+and+prepositions+worksheets+with+answers PDF link annotation
    • https://static.s123-cdn-static-d.com/uploads/4449012/normal_60b083961e23e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379839/normal_5fe5563453d9a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415740/normal_603fe930a8ffb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389085/normal_60474c6f425b5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481157/normal_60c0ab802e866.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4417040/normal_60b72803bb604.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403262/normal_5fca9f6f6528e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421354/normal_60137ad52abc0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378151/normal_60608c0d493ea.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478688/normal_606350660662d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420039/normal_5fd3a667a8eae.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://watapabipos.pbworks.com/f/cuanto_es_1_metro_90_en_pies.pdfIn PDF document text
    • http://fuvotobike.pbworks.com/w/file/fetch/144491061/tinenamalapirovan.pdfIn PDF document text
    • http://xiwitanul.pbworks.com/f/mashed_cauliflower_recipe_instant_pot.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84204b9d-0cc8-4883-99f9-54a0073dc324/where_are_secop_compressors_made.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/52f7116a-871e-4b17-9493-30e561f85f25/20284421374.pdfIn PDF document text
    • http://mikabipi.pbworks.com/f/sesetunejekofoxema.pdfIn PDF document text
    • http://jolunatimavu.pbworks.com/f/acupressure_books_free_download_in_hindi.pdfIn PDF document text
    • http://tasonupopam.pbworks.com/w/file/fetch/144505650/darth_bane_dynasty_of_evil_ending.pdfIn PDF document text
    • http://sujagajo.pbworks.com/w/file/fetch/144619191/67795842181.pdfIn PDF document text
    • http://kesowununak.pbworks.com/f/algebra_2_chapter_3_test_form_a.pdfIn PDF document text
    • http://palejemevat.pbworks.com/f/papalia_desenvolvimento_humano_livro.pdfIn PDF document text
    • http://xinunubaz.pbworks.com/w/file/fetch/144551952/letters_to_a_young_writer.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_off0000c86f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC86F 5408 bytes
SHA-256: 44f16a5d7f4f50429708c6f6dedb1cf280db500fa2a29f336b1000480aa8123e
font_01_sfnt_off0000daec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAEC 10192 bytes
SHA-256: d5b3a9dc780ae105cb6097cb8265140710a6000e2827f0e00b533baefc75521d