Malicious PDF — malware analysis report

Static analysis result for SHA-256 5745c4618e3bec85…

MALICIOUS

PDF

76.5 KB Created: 2021-09-18 19:01:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 72225f6965906ac0fedc1713570cf984 SHA-1: 44dc07dd0e00e3ca8bcdeee1f453eb10b4a83692 SHA-256: 5745c4618e3bec8576de83eee393adafd153f73298a13b1528e11e48765debf5
96 Risk Score

Malware Insights

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

The PDF was identified as malicious by an ML classifier and contains numerous links, many pointing to compromised CMS uploads or disposable hosting, indicative of a link farm. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to facilitate redirection. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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 http://195exim.com/datas/files/sitorawirojotuxoguze.pdf In PDF document text
    • http://inwallendorf.de/userfiles/file/93040489579.pdfIn PDF document text
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/68224193004.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/bajapisisa.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/b7p6aqma0fqvbi4o6bi8ialsn5/nalipoburibitetivezabi.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/3bfe23f36946874c6e4615d60563350d/22160248604.pdfIn PDF document text
    • http://numere-mopede.ro/mm/file/pitunabejewebugixo.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/37835135211.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/guleb.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/fanofawi.pdfIn PDF document text
    • https://dom4m.com/userfiles/files/39276631364.pdfIn PDF document text
    • https://eko-briketes.lv/userfiles/files/98785738040.pdfIn PDF document text
    • https://tekmaker.com/upload/files/kemez.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/85770830831.pdfIn PDF document text
    • https://spheresignal.com/app/webroot/userfiles/files/45252756498.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/ec7109f4d47537e34dfeeb503e11e069/19611619305.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/guziwixekulinepuxebe.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/95587308499.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/44131508554.pdfIn PDF document text
    • http://cp-1.ru/userfiles/files/danawisejelimiwuwarajovef.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/19534003723.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea69bd4217---33440250216.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=redmi+2+prime+custom+romPDF link annotation
    • 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_off0000c542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC542 10628 bytes
SHA-256: 20f0870ea61147fb1113a868aaf7750766e459d97e2051de75de8ef145ca16a6
font_01_sfnt_off0000dd9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD9F 18068 bytes
SHA-256: 054cd735c026e8c77f08c07ebf100d655680641367b5543af98688022063d19c
font_02_sfnt_off00010cbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1