Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c109df6b53758f…

MALICIOUS

PDF

82.8 KB Created: 2021-10-05 15:06:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 71da6fe8da515039fa3f345ca3c7ee9d SHA-1: e832959556b6fca8213026a493187102ae94b859 SHA-256: a1c109df6b53758f3fe98dade10a5c68cb4e177529a1b42203669bc0de4ffd26
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm with numerous URLs hosted on compromised websites, suggesting a phishing or malware distribution scheme. The heuristic firings indicate the PDF is designed as a link farm on disposable hosting, likely to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://smidgel.ru/uplcv?utm_term=grade+8+math+test+with+answers+pdf PDF link annotation
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614e4c78de171---bonomofuniguwep.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/95bd7f5263c1d89c0c05f283e0645f59/26775490630.pdfIn PDF document text
    • http://klgd.spokoino.ru/i/upload/files/54139321343.pdfIn PDF document text
    • http://alajwakh.com/uploaded_files/userfiles/files/vemuzusa.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/39571958439.pdfIn PDF document text
    • https://storycycle.com/ckfinder/userfiles/files/96265109978.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/44623743726.pdfIn PDF document text
    • https://billard-hauri.ch/userfiles/file/toxabidad.pdfIn PDF document text
    • https://firsathosting.com/calisma2/files/uploads/37819555213.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/gijotokivazokitesed.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1615b849a83322---36084956530.pdfIn PDF document text
    • https://anitacalderon.com/ckfinder/userfiles/files/96465392900.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/bejakudotimunuxor.pdfIn PDF document text
    • https://futurefacesnyc.com/uploads/file/rogona.pdfIn PDF document text
    • http://lncxjzxxw.com/upload_fck/file/2021-10-4/20211004020417899385.pdfIn PDF document text
    • https://madame-tina.com/ckfinder/userfiles/files/bagoporaxus.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/96530154908.pdfIn PDF document text
    • http://financesnadno.cz/upload/file/69812616208.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/c4ed9f294dadedee68f46d9a6fe55fc1/guxuzez.pdfIn PDF document text
    • http://zbigniewrodak.pl/galeria/file/99763209930.pdfIn PDF document text
    • https://bagstyle.uz/images/file/xagidexupupi.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_off0000dc3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f451.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF451 18704 bytes
SHA-256: 62146c28c12aea992b69c3996d32db41553b3e6819a7dd03be78956d3bef64dc
font_02_sfnt_off00012428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12428 10928 bytes
SHA-256: b8f290805653de5085ece7714ce77d5910cb7922f06ef432ba5fc3965ed4845c