Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a591e271a5b87d8…

MALICIOUS

PDF

78.2 KB Created: 2021-09-24 02:00:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d6a43dde0335fa5214fbf3d22e02d56e SHA-1: 6291a8be52c403cf45f2ce44169dacdba5ffaa73 SHA-256: 9a591e271a5b87d8f560ebb7210037f5dfd66f4b4ca56aa342a3c7db7e45e9ad
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file exhibits characteristics of a malicious document, including malformed streams and a high ML classifier score. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to potentially malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://shanghaiqingchen.com/upload/files/nagululig.pdf In PDF document text
    • http://tai-yang.tw/taiyang/upload/file/94843729412.pdfIn PDF document text
    • http://short-story.ru/upload/file/90947092099.pdfIn PDF document text
    • http://spokoino.ru/i/upload/files/wogawumora.pdfIn PDF document text
    • http://jinshi66.com/uploadfiles/files/88645816297.pdfIn PDF document text
    • http://xn--hh0b97d8is16e.com/userData/board/file/37680947695.pdfIn PDF document text
    • https://onecre.com/images/content/files/26504134266.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/236045600b844a0e55ebdbb7c24a389d/4858279475.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/nagitomuxujokarawapa.pdfIn PDF document text
    • https://nabil-doukali.com/userfiles/file/45014907552.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/28115194656.pdfIn PDF document text
    • http://americasbestwingspa.iorderfoods.com/uploads/files/44195070576.pdfIn PDF document text
    • https://ikincielinmak.com/upload/ckfinder/files/furipulavupotuxaxuzux.pdfIn PDF document text
    • http://mottaing.eu/userfiles/files/76141073381.pdfIn PDF document text
    • http://araratmebel.ru/img/file/nosovujirijujowimawomewo.pdfIn PDF document text
    • https://liho.cz/UserFiles/File/34130060435.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/23140925216.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/sufubisisuzilodiki.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161401f5ab3d5b---dadadifedomubex.pdfIn PDF document text
    • https://ietc-oman.com/userfiles/files/finuvadisu.pdfIn PDF document text
    • http://a-b-i-s.net/layout/bilder/file/rewodamirosenutefed.pdfIn PDF document text
    • http://chokmanee.com/userfiles/file/18323133145.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=pdf+to+jpg3PDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ba13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA13 15972 bytes
SHA-256: 625e19aeb9184b8682e7dd1be58f05d143eec66fe5f5f8adf2a3a8dfd37588a0
font_01_sfnt_off0000e32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32B 10172 bytes
SHA-256: 11220704e0afbb6e33742631062aff864bb271eed1c54d22a7dc6f2fb16ffc55
font_02_sfnt_off0000f9df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000111f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111F0 17100 bytes
SHA-256: f0bc92d33481478c164c5309fdbe4ddf30fd50f3b3797bb7425ef43c6c060f33