Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb5500af2e2cf96a…

MALICIOUS

PDF

82.2 KB Created: 2021-09-13 20:17:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e111923219990dafa510bf0e7c0729f9 SHA-1: d36b3a78b3000de4105f2966e3d1063a8d6f931c SHA-256: cb5500af2e2cf96a7e07e589e2dd5fc3868ba8c479502967bea192caecb0aa3e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous embedded URLs pointing to various domains, with one heuristic specifically identifying it as a link farm on disposable hosting. The presence of external URIs and the overall structure suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://wastran.ru/uplcv?utm_term=copy+sms+messages+to+new+phone PDF link annotation
    • https://relans-nn.ru/images/docs/file/maxodoripiwovukirimuf.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/33723951287.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/24858805760.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/fuwijonapotekuxolupi.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/87622551046.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/11550415751.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/15316164485.pdfIn PDF document text
    • http://thietbibepnhahang.net/media/files/figutalozor.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/jebelupegepire.pdfIn PDF document text
    • http://starroadchina.com/userfiles/file/48857338197.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613797f15f170---9280028648.pdfIn PDF document text
    • http://www.larucheapain.fr/ljk/file/25079798152.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/90430287161.pdfIn PDF document text
    • https://www.fangjin.org/ckfinder/userfiles/files/ruxez.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/xafebasusax.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/48671839449.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613e198822036---xepalofujuvepikebufudo.pdfIn PDF document text
    • https://smg.bid/ckfinder_userfiles/files/81827884088.pdfIn PDF document text
    • https://koncnc.com/genelresimler/file/21775719464.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/zokemekesurudidiluvixapax.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/10574122265.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/dikuruwimodupijasim.pdfIn PDF document text
    • http://fcvperu.org/data/fcvperu/userfiles/file/89324939820.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/wexabam.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_off0000dc50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC50 18076 bytes
SHA-256: b174ab6c1257d02b780cc355a47aa3d15727a9528b879467284b8ea78027fd7d
font_01_sfnt_off00010b20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012337.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12337 10692 bytes
SHA-256: 3298e4ff3542ce90af8086d22a4ed512e3a3957d2ab0f657a174db33a9ec557e