Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fd8e8661d0b55ed…

MALICIOUS

PDF

79.8 KB Created: 2021-06-07 03:28:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5baca1d3d750ce35d9662052006db56e SHA-1: 3d116a5bab0f88fdd3bcf8cf41d576bbcfc7ad35 SHA-256: 8fd8e8661d0b55ed702fa5631ff497af43bce1cc1f002f536f96524fb0a94ff2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains heuristics indicating it is a link farm and a lure for clipboard command execution. The ML classifier strongly flagged this PDF as malicious. The presence of external URIs and the specific heuristic 'SE_CLIPBOARD_COMMAND_LURE' suggest the document's intent is to trick the user into executing commands, likely to download and run a secondary payload. The ClamAV detection further supports its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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://inwebjor.ru/pbw?utm_term=free+bootloader+apk
    • https://static.s123-cdn-static.com/uploads/4455916/normal_5ff94d79d1f09.pdf
    • https://cdn-cms.f-static.net/uploads/4481273/normal_5fe654af285ce.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://vafakana.pbworks.com/f/44161762073.pdf
    • https://uploads.strikinglycdn.com/files/c90afecf-e0f6-4494-9679-849096a0b04d/machine_learning_explained_ppt.pdf
    • http://mutoteja.pbworks.com/w/file/fetch/144521913/xogadimaxugefimo.pdf
    • http://zuwofig.pbworks.com/f/91938926868.pdf
    • https://uploads.strikinglycdn.com/files/fcdbf716-8aa8-437b-9841-40119a8aff02/estructura_6.1_saber_and_conocer_worksheet_answer_key.pdf
    • http://wefolevemud.pbworks.com/w/file/fetch/144438027/algebra_y_trigonometria_sullivan_novena_edicion_solucionario.pdf
    • http://wojipag.pbworks.com/f/54145092979.pdf
    • http://gegoxelaw.pbworks.com/w/file/fetch/144687129/98291069843.pdf
    • http://wabiwepakeg.pbworks.com/w/file/fetch/144708420/the_courage_to_be_disliked_main_points.pdf
    • http://jobagej.pbworks.com/w/file/fetch/144572118/gta_5_kurulumsuz_indir_windows_7.pdf
    • http://vugufosenene.pbworks.com/f/how_do_i_activate_my_att_personal_hotspot.pdf
    • http://funuvutidip.pbworks.com/f/mitutolivuxivija.pdf
    • http://deduxofevit.pbworks.com/w/file/fetch/144664233/autodesk_3ds_max_2018_xforce_keygen_download.pdf
    • http://lururefisu.pbworks.com/f/15999384735.pdf
    • http://rawumadakora.pbworks.com/w/file/fetch/144751737/adjustment_disorder_with_mixed_anxiety_and_depression_dsm_5.pdf
    • http://wotasaful.pbworks.com/w/file/fetch/144678438/como_transferir_musica_iphone_para_iphone.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6c9.bin
5ef307d4a658db3046501f4bd32caaf45453634ae7b9ef1d4313d0a34ffe4258
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C9 4932 bytes
font_01_sfnt_off0000f79d.bin
c70596545b1fa96f69f6e177729bafa47978c385f4c2c5933dbc49fe3ed5be2b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF79D 10856 bytes
font_02_sfnt_off00011ceb.bin
c988415812f594187b0a0ed75dc52802e798e1695b49bd300f8412a65040a449
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CEB 16204 bytes