Malicious PDF — malware analysis report

Static analysis result for SHA-256 637978fc8416146a…

MALICIOUS

PDF

96.4 KB Created: 2021-04-03 12:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: effce1d05d37b575846d507743f6ac3f SHA-1: e91132aa1fd7621e819160400dfffed7a989501a SHA-256: 637978fc8416146a1fb60fcc375e46e256988717d6bb3b7f2ae29d35dbb13e01
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, with a primary suspicious URL pointing to a domain associated with phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for link farms, further suggesting malicious intent. No scripts were extracted, but the presence of external URIs and the overall heuristics strongly suggest a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • 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.
  • 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://midufefew.ru/award?keyword=kavach+argala+kilak+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4492555/normal_5fd138b5bbd6d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424997/normal_5fcc61b81745d.pdfIn PDF document text
    • http://bavimobuxadu.medianewsonline.com/dark_souls_2_save_editor_xbox_360_download.pdfIn PDF document text
    • https://cdn.sqhk.co/tisufupujeli/hbigZ5M/hakuouki_season_2_episode_2_english_dub.pdfIn PDF document text
    • http://usacreditmonitoring.info/marlin_model_60_stainless_steel_scopeksj3y.pdfIn PDF document text
    • http://ponemofetu.scienceontheweb.net/vishnu_1008_names_in_sanskrit.pdfIn PDF document text
    • http://supernefritroller.xyz/jikomusevoketomg5uha.pdfIn PDF document text
    • http://rogevunesopu.medianewsonline.com/ajp_taylor.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448121/normal_5fca9559215bc.pdfIn PDF document text
    • https://cdn.sqhk.co/xekobigi/hcjdTHt/bole_chudiyan_bole_kangna_song_raagsong.pdfIn PDF document text
    • https://cdn.sqhk.co/jaxaletadi/Ehb1BY8/max_dtr_4_cylinder_setup.pdfIn PDF document text
    • https://cdn.sqhk.co/wovovoteg/hbX0iiB/37710299015.pdfIn PDF document text
    • http://sallehub.xyz/77126753119aebcx.pdfIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wixamupelinere/jitekozavar.pdfIn PDF document text
    • http://pivimufe.atwebpages.com/62329413431.pdfIn PDF document text
    • http://molujafit.atwebpages.com/anoxia_neonatal.pdfIn PDF document text
    • https://85d2c5a2-fc31-4f76-86b4-4ebe2abe2bf4.filesusr.com/ugd/a8cc01_731759cb142e4b2bbac481fbb53b17c9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tizowodifi/zijipajok.pdfIn PDF document text
    • https://s3.amazonaws.com/rodakarugupoko/fisher_price_rainforest_jumperoo_accessories.pdfIn PDF document text
    • https://4ec63ec4-77bf-4499-900e-7c522af20654.filesusr.com/ugd/35bdb9_3d409e4d7fdb4fb5b5f8325dd9c66fc0.pdf?index=trueIn PDF document text
    • https://711920be-b761-4f0e-a604-762b26663b16.filesusr.com/ugd/ffcbea_51ff78e8ca9d45718cc504152e90711e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/takurugilij/adhd_symptoms_checklist.pdfIn PDF document text
    • https://4c6480a9-ccec-4c20-853c-cc48681c44ad.filesusr.com/ugd/935adc_65f55feed3f947b191674f5962fc9f6f.pdf?index=trueIn PDF document text
    • https://d7b50aa0-fea3-4edc-ba9e-4ed0094b0c60.filesusr.com/ugd/7f614e_2627f99d6aba4ae0b2e3d1171a9f7f16.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
stream_004_off00013707.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x13707 20100 bytes
SHA-256: f2ac74c007d3e57f87cbf85a9d03b6829cfa5fdde80bcb893d3a720545d41279
font_00_sfnt_off000101a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A1 5332 bytes
SHA-256: fd5fee756ce4853ed65f520fb3c6eda041a2639cba27c2286095f138404e8f05
font_01_sfnt_off000113cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CC 10188 bytes
SHA-256: 8aa522ea53a7bc03c4600486c30643dfae3ba6a449b4a588166cf0770844841f