Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6d136ed8a520593…

MALICIOUS

PDF

80.4 KB Created: 2021-09-20 18:53:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: c6aa69f1b77ce55ec0ba0c5763175514 SHA-1: 4e3725cd8a1a0a74dc7f70a7751f1f65966cbf7b SHA-256: b6d136ed8a52059351905ece34edafbb4601da72bf13b3082310a5d12c911622
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://medvor.ru/uplcv?utm_term=fire+strike+online+apk PDF link annotation
    • http://sbstroy53.ru/img/files/94643938105.pdfIn PDF document text
    • http://ned.ru/uploads/files/boxumigitasim.pdfIn PDF document text
    • https://martan.es/cenavarra_userfiles/files/67131574059.pdfIn PDF document text
    • http://jagodkaprzedszkole.pl/userfiles/file/kazoridesodoze.pdfIn PDF document text
    • http://sm300159.agchost.com/userfiles/files/vamibir.pdfIn PDF document text
    • https://bursakaynak.net/userfiles/file/xalemivekax.pdfIn PDF document text
    • http://mimarkamilozkartal.com/userfiles/files/439676075.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210919_17B9C65D1D81730B.pdfIn PDF document text
    • https://konchris.com/userfiles/file/1631361596.pdfIn PDF document text
    • http://nanumed.ro/uploads/files/60469678900.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/4ab249c977f20981c0eb6a7ab0489749/voreg.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/78775177579.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613058f0379d9---fokajor.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/61437766588.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/woxut.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/48850939051.pdfIn PDF document text
    • https://marblobathware.ph/app/webroot/img/files/loniwuxufazupofojutuketef.pdfIn PDF document text
    • http://meuble-tunisie.com/userfiles/file/gonefaleviwot.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/bodadajifetugomezatower.pdfIn PDF document text
    • http://donghotam.com/luutru/files/rufojunevixifipudizapu.pdfIn PDF document text
    • http://evrofurnitura.by/elax-furnitura.ru/uploads/files/nusolojuzixedalaxi.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/tulogakixepenakidet.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/fubuzas.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/sidibamuvol.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_off0000d539.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD539 18104 bytes
SHA-256: 4ce7606b08f9a986673c532b4f3d6f29f1b1fa9a25e370cbed8cb7de271d78d7
font_01_sfnt_off000104d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104D2 10316 bytes
SHA-256: 2aaec6207575d143f33034a180b64be0770b3229eafc07e595c221823134f047
font_02_sfnt_off00011c35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1