Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fdd7a9516aee1c3…

MALICIOUS

PDF

85.2 KB Created: 2021-09-10 11:56:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fc6081a9154d4d06692be6d5ad3959ab SHA-1: 51cef8c4f5c3eb6c726b9f9bb035b0d7e08839d9 SHA-256: 4fdd7a9516aee1c34627295b548c0ada61e6705bcb12fa76110ac38d61638c9a
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to other PDFs hosted on disposable domains, indicating a link farm designed to obscure the true malicious destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the PDF structure and numerous external links point towards a social engineering attack to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://thuaphatlaihanoi.net/uploads/files/36043948097.pdf In PDF document text
    • http://toroisg.com/public/images/files/rebapalagujezej.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/xuxinexirexok.pdfIn PDF document text
    • http://lamekatus.com/uploads/ckeditor/files/baxetirujex.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/pujefimulokerunesi.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1630832693.pdfIn PDF document text
    • http://chornakorn-packing.com/ckfinder/userfiles/files/puzalelikexumetixegaraze.pdfIn PDF document text
    • http://140.121.180.103/ckfinder/userfiles/files/51777918318.pdfPDF link annotation
    • http://logtech.cz/foto/Image/file/28903351889.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/38157928612.pdfIn PDF document text
    • http://web5gstore.com/Files/files/dapiregikam.pdfIn PDF document text
    • http://osstemcardiotec.com/files/fckeditor/file/1143950096612ece1a9ee82.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/98532820382.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/jazukijipil.pdfIn PDF document text
    • https://teamcode.net/upload/files/xakeparevemuwu.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612ebd673f30d---94529542621.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/1476460841.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/kifiremo.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/1883051100.pdfIn PDF document text
    • http://violetstudio.in/userfiles/file/fonazina.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/89754834041.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/89593918697.pdfIn PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/55210315422.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/danovimixir.pdfIn PDF document text
    • http://tutaylamhet.com/storage/ckfinder/files/zetokimuwobizenokapav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=free+genealogy+apps+for+androidPDF 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_off0000e938.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE938 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001014a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1014A 17988 bytes
SHA-256: 0f8ce3bdf1390d10acd79d068eb50c12665dbbc93c6cf1ce62ec2249dcf1e277
font_02_sfnt_off00012f61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F61 10668 bytes
SHA-256: 1bb35aa6795ccdee8a322835673d1a7c7ca3422a88acf5bd762569272cbc69f0