Malicious PDF — malware analysis report

Static analysis result for SHA-256 977db386be3c2717…

MALICIOUS

PDF

87.9 KB Created: 2021-09-21 16:37:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 42f8757f0bfdf013456b6f71cd7757ee SHA-1: 8cea0945190982e25af1a7033a405ebb4ffbcbb7 SHA-256: 977db386be3c2717ef9746a6db0a249a8be3d175e2bf192c86716d906fc7fbb3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on disposable domains, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a spearphishing attachment used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://bcbc3399.com/upload/files/tujesomogulowe.pdf In PDF document text
    • http://wwstationery.com/files/file/53520043672.pdfIn PDF document text
    • https://lawyerupsmart.com/tempimg/file/64710604884.pdfIn PDF document text
    • https://phuquiland.com/upload/files/7922639936.pdfIn PDF document text
    • http://bluebossa.pl/files/file/89909914846.pdfIn PDF document text
    • http://varadimasszazs.hu/uploads/files/86824251671.pdfIn PDF document text
    • http://starinviter.com/ckimagefiles/diwigafawexarop.pdfIn PDF document text
    • http://cattaneoarchitetti.it/userfiles/files/vuzisoborewelizalela.pdfIn PDF document text
    • http://ladyvenus.it/userfiles/files/56359671364.pdfIn PDF document text
    • http://robbes.nl/media/files/junobamagazaka.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/gesesam.pdfIn PDF document text
    • http://sukhonthip.com/file_media/file_image/file/luxafijinugufigude.pdfIn PDF document text
    • https://k85shj16h-561lt.com/contents/files/19867687817.pdfIn PDF document text
    • http://dunajecbiala.pl/upload/File/1426206887.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/56788954845.pdfIn PDF document text
    • http://karpatskiles.ru/store/file/babixazapewif.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/tasazuxizifogoka.pdfIn PDF document text
    • http://krukewittfarms.com/userfiles/file/tajamijozakakugebabiriru.pdfIn PDF document text
    • http://ajitcoatings.com/uploads/wosopatidasule.pdfIn PDF document text
    • http://playbabydoll.com/userfiles/file/japoget.pdfIn PDF document text
    • http://laserbeautymachine.net/d/files/8507499472.pdfIn PDF document text
    • http://www.huntsvillepr.com/files/files/76768878780.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=chess+3d+para+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_off0000f38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF38D 10548 bytes
SHA-256: 655ad3c6b91463a6a9e688728d97045d38fa7107dcd48e7c85598710ce56c188
font_01_sfnt_off00010b85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B85 18112 bytes
SHA-256: dd254084a4f7da3e8d89cbdec35d11c2b8c00c4e8ff5ab368389c63d34daa5ea
font_02_sfnt_off00013a65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1