Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f6341a8f790b39…

MALICIOUS

PDF

82.7 KB Created: 2021-09-18 21:18:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 53256d6c1275d66108d0f64307a16518 SHA-1: a98bd71abb92714d94cab1390096b3f9c6c338a0 SHA-256: a9f6341a8f790b39c2be1560e14069831c72b6ad067eae7e9023899f5217eaf4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, suggesting a phishing or malware distribution attempt. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates this behavior. No scripts were extracted, but the presence of external URIs and the overall detection profile strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://nomylo.ru/uplcv?utm_term=gameboy+advance+emulator+pokemon+games PDF link annotation
    • https://cgeminfos.ma/upload/file/15769680305.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/34974543636.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/59605844345.pdfIn PDF document text
    • https://michelbarbot.com/upload/files/51925142399.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/97227976074.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/jakuz.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/xetekiwokujub.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613254ced6dd7---wugureg.pdfIn PDF document text
    • http://raylutickenterprises.com/userfiles/files/67081291702.pdfIn PDF document text
    • http://uni-soar.com/userfiles/file/53726667795.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/zurubivulofibejogedo.pdfIn PDF document text
    • http://m3hotels.com/userfiles/file/lixuzeresimazik.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/38582039169.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sozir.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/82918397220.pdfIn PDF document text
    • https://waelfawzy.com/userfiles/file/In PDF document text
    • https://bosgo.mn/uploads/files/belonerivelusijigefelave.pdfIn PDF document text
    • http://i-physiology.ru/upload/kazizeji.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee30de9aa7---tutubuvexixemanudabefokit.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/1122813892.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/numupojudopuburuwufupazi.pdfIn PDF document text
    • http://medizator.ru/ckfinder/userfiles/files/lafesorikibilatem.pdfIn PDF document text
    • http://s250801404.onlinehome.fr/img/uploaded/file/ginevinij.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_off0000dc29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC29 17976 bytes
SHA-256: 35356e122ea7c12e1ec76bd0c710f0a9c4c8394f93badbf9e6f870ed9fe919b3
font_01_sfnt_off00010ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB2 11316 bytes
SHA-256: 61e257a68773a38394efcf0583460bf30f0afe7a1859294f1d504fa25f6db975
font_02_sfnt_off000124f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1