Malicious PDF — malware analysis report

Static analysis result for SHA-256 981ed6de94774efa…

MALICIOUS

PDF

79.6 KB Created: 2021-05-07 06:33:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: a0bfbf86df268c53b4e984c56fc44920 SHA-1: c8d3637c3d3643efa4fe6ed4cbc9aa6bfc9e7a83 SHA-256: 981ed6de94774efa28ad08074261e16277981109bc8827fa986ad90a8026aec7
146 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including malformed streams and ML classification flagging it as malicious. It also includes numerous URLs, some of which are hosted on disposable domains and appear to be part of a link farm designed to redirect users. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports the malicious classification. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, suggesting it was generated programmatically to appear as a document, likely to disguise malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://zajinet.ru/strik?utm_term=how+to+learn+handwriting PDF link annotation
    • http://getveran.site/46068197778glipd.pdfIn PDF document text
    • http://ecoservice-vlad.ru/exemple_de_bon_de_livraisonwtlja.pdfIn PDF document text
    • http://neojust.ru/wosuzuzogilitesaliljzgkp.pdfIn PDF document text
    • https://cdn.sqhk.co/fasazani/ihghb3d/thunderstorm_3d_live_wallpaper_for_pc.pdfIn PDF document text
    • https://dowusezawidi.weebly.com/uploads/1/3/3/9/133997386/420fe.pdfIn PDF document text
    • http://mabisipi.iblogger.org/california_paternity_leave_law_2020.pdfIn PDF document text
    • http://gouliwer.online/jam_chillout_speaker_reviewps06c.pdfIn PDF document text
    • https://wolaserirefuf.weebly.com/uploads/1/3/1/6/131637046/f68690.pdfIn PDF document text
    • http://natgood.space/car_crashes_news_reports2t48d.pdfIn PDF document text
    • https://xakebugus.weebly.com/uploads/1/3/4/0/134018628/2882207.pdfIn PDF document text
    • https://muwobifuf.weebly.com/uploads/1/3/4/5/134501600/karotuworutejisisi.pdfIn PDF document text
    • https://cdn.sqhk.co/monasomeb/gd7aibV/cooking_dash_chateau_creep_season_4.pdfIn PDF document text
    • http://new-volosi.ru/12777440445zxscl.pdfIn PDF document text
    • https://cdn.sqhk.co/dewavasese/aZGk5P3/football_soccer_strike_soccer_star_football_game_2018.pdfIn PDF document text
    • http://italylife.pro/sole_f80_treadmill_customer_reviewsubfra.pdfIn PDF document text
    • https://tomoniwibisuxis.weebly.com/uploads/1/3/5/9/135961627/jopizujomopese_lipujuk_noluxufofod.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
    • https://s3.amazonaws.com/rowubunak/19334141667.pdfIn PDF document text
    • http://tuwuxadifire.rf.gd/harbor_breeze_ceiling_fan_manual_instructions.pdfIn PDF document text
    • http://ninivekav.rf.gd/atharva_veda_malayalam.pdfIn PDF document text
    • https://s3.amazonaws.com/rawesaragegugar/warning_sign_coldplay_piano_sheet_music.pdfIn PDF document text
    • https://s3.amazonaws.com/tozaduliwubega/cancer_de_prostata_tratamento.pdfIn PDF document text
    • http://josekopiguvalup.epizy.com/sundance_spa_sentry_850_parts_diagram.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_off0000ed02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED02 4748 bytes
SHA-256: c87d3ba59eb72ada8c545fa86cbba1c214fd24cdbf96ba1850c80eebdbbb2fc7
font_01_sfnt_off0000fd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1F 10984 bytes
SHA-256: f14f2550f820555b4cf42a3d44eb050b69cecbd46398636716d167493b8aaea8
font_02_sfnt_off00012272.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12272 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3