Malicious PDF — malware analysis report

Static analysis result for SHA-256 031259d2a0148fdd…

MALICIOUS

PDF

79.1 KB Created: 2021-09-11 15:16:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c73f5431ec9f05c6578d36c0c05bd0a9 SHA-1: 8868e4961bc84bbe8573ee8b307d6cdbd3be2e39 SHA-256: 031259d2a0148fdd8b067a0e2bc7c0145d14f19b3f820ea16cf0b7a5c509f425
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=billy+cash+loan+apk PDF link annotation
    • https://argekaucuk.com/nbg/upload/files/10090670747.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/lsaah2j1spffvjfr23abgjl6pu/42707576681.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/3961d984e09b4ca95bf0f33d1088e929/mapejunelemafow.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/tejaremerugabenoripulo.pdfIn PDF document text
    • http://isgsrl.it/images/file/rusilutukumikuwe.pdfIn PDF document text
    • http://pk-rowery.pl/user_pict/file/wudifawofinajefuzilera.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/72021659887.pdfIn PDF document text
    • http://warehousetraining.ie/images/kutizigunipubegefaxub.pdfIn PDF document text
    • http://leoclubmarsala.it/userfiles/files/zadejog.pdfIn PDF document text
    • https://abriganature.centralcms.cloud/galeria/files/95938536020.pdfIn PDF document text
    • http://vanlysecurity.vn/vanly/album/files/66114489511.pdfIn PDF document text
    • http://erpos.sk/data/files/48432988861.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/wujefurolefidu.pdfIn PDF document text
    • http://lexuspolymers.com/assets/ckfinder/userfiles/files/zodijajunabubopedi.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/80711024734.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/bimalalerarogutureter.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/nafovisemugosojedajeteve.pdfIn PDF document text
    • https://12shio1.com/contents/files/momuriwogapu.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/6129425354.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/80664543628.pdfIn PDF document text
    • http://isleford.com/filespath/files/20210907175905.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613766294b2b4---63698018503.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139be56a22ff---92825108314.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_off0000cee7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEE7 18588 bytes
SHA-256: 89d4f42a5f5f0bf80dd809a5bb07a28f12ff5bfdb3cce68e8fc2f6c88b8dfdc8
font_01_sfnt_off0000ffe8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE8 10400 bytes
SHA-256: 3b68342c14e74070cf6224701ece5a2b43b5e67a998a50251973a535527020b1
font_02_sfnt_off0001176f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1176F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1