Malicious PDF — malware analysis report

Static analysis result for SHA-256 873c3c99da3fb766…

MALICIOUS

PDF

75.0 KB Created: 2021-04-06 14:32:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 76290e3e5142af5195a85f9e1d9e0790 SHA-1: 71b89e01e009308b849c1b30d15f31c98abe6b53 SHA-256: 873c3c99da3fb766385743335f235a045c942afb3529be1590e960fa86ecb8f4
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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 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://crophysi.ru/award?keyword=how+to+change+pdf+to+word+document+on+mac PDF link annotation
    • https://cdn.sqhk.co/xanikadir/9giH7hc/gabriel_s_oboe_organ_sheet.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415929/normal_5fe0bb114d5cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369158/normal_6024562052542.pdfIn PDF document text
    • https://cdn.sqhk.co/wotudasigeb/bsIiaeg/rowdy_baby_song_audio_masstamilan.pdfIn PDF document text
    • https://cdn.sqhk.co/kedezoge/dghjzV9/sakuwu.pdfIn PDF document text
    • https://cdn.sqhk.co/nezerozara/ihcOSig/lyft_driver_won_t_pick_me_up.pdfIn PDF document text
    • https://cdn.sqhk.co/revinoxu/gieCGcB/500_pictures_how_many_gb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408865/normal_5fea3d91a1480.pdfIn PDF document text
    • https://cdn.sqhk.co/zubuwebofe/hfZHia6/rolling_ball_sky_music_dancing_ballroom.pdfIn PDF document text
    • https://cdn.sqhk.co/jasowipe/NhcHjeC/fizefo.pdfIn PDF document text
    • https://cdn.sqhk.co/tosobulig/gkY7FYE/radiant_defense_brush_cleaning.pdfIn PDF document text
    • https://cdn.sqhk.co/xusarukave/1dhdGgg/atomic_model_of_oxygen_atomic_number_8.pdfIn PDF document text
    • https://cdn.sqhk.co/wejagamewo/jdjaief/lagu_back_at_one_cover_amara.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/ribowexulo/introduction_to_atmega32a_microcontroller.pdfIn PDF document text
    • https://e6e31949-ba74-43ae-8e0c-2243355e89fd.filesusr.com/ugd/69e259_dd57b38ef9354b95ac35f93889236773.pdf?index=trueIn PDF document text
    • https://a04ad255-06d6-4b17-97e7-91173d300295.filesusr.com/ugd/6864df_5fdad788ca3b4789aed56e8c4e70febd.pdf?index=trueIn PDF document text
    • https://9f5bcc56-a059-4f00-ae85-604acd6a3d2d.filesusr.com/ugd/ac9354_d8d40685e0d148199805a33ffae827e9.pdf?index=trueIn PDF document text
    • https://f499a9ea-5579-4d3c-a180-ba191067f9b7.filesusr.com/ugd/34ec99_0ccd6dd3fafb4faea2f950c4bdaa9e5a.pdf?index=trueIn PDF document text
    • https://80ce5912-1c67-4773-adf4-abf614566e91.filesusr.com/ugd/acb48a_7f9cc0be068746cebe0946654cd97bf8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bulikowexunepov/sevoxufodufetukib.pdfIn PDF document text
    • https://s3.amazonaws.com/pusolefosex/8667387207.pdfIn PDF document text
    • https://s3.amazonaws.com/livivuvuwugeb/broadcaster_bouquet.pdfIn PDF document text
    • https://s3.amazonaws.com/zonebon/33216485661.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_off0000e620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE620 5412 bytes
SHA-256: 2e883cfdee05c4d5971c7b385ea5fd7a294b607eff36282c5e70782cedc033a2
font_01_sfnt_off0000f87a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF87A 11008 bytes
SHA-256: 5041d3c710164ab29fefec5cfb3b8fc13b5e584d848a17d01abc1dae3f3fc6f5