Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5f227757a118327…

MALICIOUS

PDF

69.9 KB Created: 2021-09-28 11:50:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5f79510f6582eadb2a226f912e71db58 SHA-1: 23a3def35b67ca360ec9d03f63af4943242b04d9 SHA-256: c5f227757a118327481e29a9e101452a8655dff26673129d6c0eb9a55e12ebb2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs that function as a link farm, directing users to various websites. Several heuristics indicate that these links are hosted on disposable or compromised domains, suggesting a phishing or malware distribution scheme. The ClamAV detection and ML classifier further support its malicious nature, likely exploiting PDF vulnerabilities to execute further actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://garglob.ru/uplcv?utm_term=rtf+to+pdf+online PDF link annotation
    • http://www.deep2001.com/images/library/File/29620858622.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/178068706661461f53015bf.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/38833432912.pdfIn PDF document text
    • http://breakevenpoint.pl/uploads/editor/file/lewowijuwadibagaxilene.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/ravufunevosowumoxifutozig.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141fa7bc7450---59241479230.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/51719598833.pdfIn PDF document text
    • http://octapus.vn/images/uploads/files/40056047843.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133e757d9a89---bulufefosideduxijumu.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210916172024.pdfIn PDF document text
    • https://styliststudios.com/imagesTE/file/68363501033.pdfIn PDF document text
    • http://irina-beha.com/ckfinder/userfiles/files/98076993639.pdfIn PDF document text
    • http://pecsimutargygaleria.hu/files/file/35568224602.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/ponujukuwugu.pdfIn PDF document text
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/40644047639.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/zifideloxurulexonizugave.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/sifik.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/texoji.pdfIn PDF document text
    • http://bourgogne.annuaire-regional.com/ckfinder/userfiles/files/26962931718.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146be11bc348---gukelevitowatigovaxe.pdfIn PDF document text
    • https://whitesal.com/data/images/file/8176_20210920083244.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/sizovonurusoro.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_off0000b165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB165 16620 bytes
SHA-256: 792b2f52bdee47baf6cb263a5ee50eced197d8d085ec33d621e7f9c1383b33f0
font_01_sfnt_off0000dc02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC02 10108 bytes
SHA-256: 97bac2bbdf70602df5c29adb5af488cea0edda32de475d9cd5d118b87f99a1f2
font_02_sfnt_off0000f2a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1