Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b994ef5dde239dd…

MALICIOUS

PDF

79.4 KB Created: 2021-04-11 02:24:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 5b497f3881369a301e7c323eb9ad17dc SHA-1: f6fb9ac9e461a501be060a8fda8aa0328b59ca27 SHA-256: 5b994ef5dde239dd9d1b9a3d5f546b600aae7906465e818af099f3c71d0c2a1a
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, a common tactic for SEO spam or phishing campaigns. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicate this. The ClamAV detection and ML classifier further support its malicious nature. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure suggest an attempt to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kuzutuzo.ru/strik?utm_term=how+to+maintain+a+front+load+washer PDF link annotation
    • https://cdn.sqhk.co/kivipemo/CFgdiND/wobokosomapodotiw.pdfIn PDF document text
    • http://tafuvomilo.22web.org/rodozugogagogebozebajere.pdfIn PDF document text
    • http://dabubavosiwus.iblogger.org/how_to_reset_ipod_2nd_generation.pdfIn PDF document text
    • https://cdn.sqhk.co/jigavozef/9heohde/sulivupofenalimipilubef.pdfIn PDF document text
    • http://giwabuf.22web.org/how_to_fill_out_form_interrogatories.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417537/normal_5fd9dd150066b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486743/normal_60532af6a82a9.pdfIn PDF document text
    • https://cdn.sqhk.co/digipexula/caAN8Pm/73955779354.pdfIn PDF document text
    • http://ketorebagibof.22web.org/hex_guide_pathfinder.pdfIn PDF document text
    • https://cdn.sqhk.co/nakijalufiw/1hdUmeK/free_photo_collage_app_apple.pdfIn PDF document text
    • https://cdn.sqhk.co/nomitusibop/dX5hejf/raxifotovarugawimosukud.pdfIn PDF document text
    • https://cdn.sqhk.co/xejexeremiso/jajghat/neurosis_definicion_english.pdfIn PDF document text
    • https://cdn.sqhk.co/jidelugob/dQDihhb/27626812669.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373517/normal_601307b31e409.pdfIn PDF document text
    • https://cdn.sqhk.co/sovanoniwuva/eOujchg/16862225425.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418365/normal_60327578df514.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://tumawom.epizy.com/smallest_reader_app.pdfIn PDF document text
    • http://magomodatibotu.epizy.com/55779486203.pdfIn PDF document text
    • https://6ba7316d-b84b-4ccb-a32a-103c856d4013.filesusr.com/ugd/91f37e_9599e1b9cd5a4e9fa1fe888f7a260c3a.pdf?index=trueIn PDF document text
    • https://6b2f37ea-3696-4b87-858b-663c379f6f6f.filesusr.com/ugd/16879a_55596d32517741d598af0384bde19637.pdf?index=trueIn PDF document text
    • https://54a0e2cb-796f-4f80-9aaf-d11633176b06.filesusr.com/ugd/b0c554_8408a1ce2c514ba4bd3507f48d5d48c8.pdf?index=trueIn PDF document text
    • http://zebinagapovu.epizy.com/xafizubimijozovovuwemuli.pdfIn PDF document text
    • https://8d5bcf17-53f2-4f21-b585-7a27aef14131.filesusr.com/ugd/7baf93_82a2ff954b1a40b8ab500999fab34886.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC85 4988 bytes
SHA-256: a1650d2f1f6762a0b5bcad9f8718910f25e7b89c70ada2e24c883ef38f43c3a2
font_01_sfnt_off0000fd4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD4E 10612 bytes
SHA-256: 2e4feb51eda24fa2520fec297659901631333b7ebdbbc9c84cd006574a286535
font_02_sfnt_off0001216a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1216A 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230