Malicious PDF — malware analysis report

Static analysis result for SHA-256 a281fa861bde4094…

MALICIOUS

PDF

70.0 KB Created: 2021-09-20 17:49:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 17758cad8fa460938a139b89f9cd6f83 SHA-1: a05e529746574b7eca1e58b0571482ca61e66659 SHA-256: a281fa861bde40942a01d3b7a66f737317ef22aec8fae2e614447e8d16c6ea6a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, suggesting a phishing or malware distribution campaign. The presence of external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly indicate a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://archism.ru/uplcv?utm_term=lbochs+pc+emulator PDF link annotation
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/nilijurelawezupuzil.pdfIn PDF document text
    • http://quaretti.it/userfiles/files/zutupoxopifaxim.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/84087215189.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/mibisuxemavamexuv.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/fuziraki.pdfIn PDF document text
    • http://novichiha.ru/pic/file/damibadibamedinumewemiza.pdfIn PDF document text
    • https://drinkpoint.com/uploads/files/feterixivukixegon.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/50237938257.pdfIn PDF document text
    • http://www.gobarging.com/uploads/textareas/file/95758086790.pdfIn PDF document text
    • https://odontologosmalca.com/images/userfiles/file/15523553528.pdfIn PDF document text
    • http://ambvetesopo.eu/userfiles/files/kajasusomozuluvitopi.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/nesifekapekagiwerim.pdfIn PDF document text
    • https://war-old.its.vn/new/userfiles/file/4947129453.pdfIn PDF document text
    • http://mislenyiallatorvos.hu/userfiles/file/gatutotemo.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/medozebofugusevigimusa.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/98010152857.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/59720002066.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/c0b8aeb1c4640ff356d4ff185b08a0f2/1411726694.pdfIn PDF document text
    • http://www.stadion-zarya.ru/ckfinder/userfiles/files/rezugajitukomewubuj.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/linajudesarisidesuranowut.pdfIn PDF document text
    • https://jills.reviewz.eu/app/webroot/files/userfiles/files/kexek.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/rekebodepetevojureju.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/6586426135.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b354.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB354 10640 bytes
SHA-256: ba5cb9243601772e379214059c48eb6ead0af03936c3fa97a1b22cf3363cdda5
font_01_sfnt_off0000cb7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE391 15196 bytes
SHA-256: 662130388a796afa1bbc7bd620b062f2924d89c3434b52290c24cd32c41d1074