Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b07a7f8d3ece26e…

MALICIOUS

PDF

81.3 KB Created: 2021-09-12 06:06:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7c240251dfe4cdddd5d299cbe75a509a SHA-1: db7b52dc285670899c47a9d3fd54e7a69068a2ad SHA-256: 4b07a7f8d3ece26e355828f4fb6bb1fe19251daadd3cb214e05a88539d93e370
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised WordPress sites. The presence of 'utm_term' parameters suggests a phishing or SEO-based lure to entice users to click on these links, which likely lead to further malicious content or exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://synerhu.ru/uplcv?utm_term=adult+comics+free+pdf PDF link annotation
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/8884d0baa922a75528ed77a054bc0b54/10688668012.pdfIn PDF document text
    • http://metall-press.ru/files/delebojitozeleronoboxu.pdfIn PDF document text
    • http://yey.uw52.com/upload/files/lujekowisi.pdfIn PDF document text
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/bibotunevuwub.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf22197577---45824227323.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/71717400598.pdfIn PDF document text
    • https://shidoremicrosys.com/media/bamopagidenabofi.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/futuxifizelepopofebalop.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/17085233205.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/65489083641.pdfIn PDF document text
    • https://internationalmedia.com/userfiles/file/69686687218.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210910_7A0F4EED6EDE5143.pdfIn PDF document text
    • http://bhttourist.com/upload/fckimagesfile/gasitigakexisopi.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210906_AE789B6194A1968B.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/nulefevarelovosifa.pdfIn PDF document text
    • http://www.eau-msu.ru/ckfinder/userfiles/files/88581325292.pdfIn PDF document text
    • http://a2hgghk.handylover.com/upload/files/bopaguremora.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/6425699929.pdfIn PDF document text
    • https://nullemont.fr/nullemont/ckfinder/userfiles/files/22719158105.pdfIn PDF document text
    • http://wxdyzs.com/userfiles/files/15021719331.pdfIn PDF document text
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/75364680002.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16138d8318034c---64077045241.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/78863872835.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_off0000da84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA84 17428 bytes
SHA-256: 8df8db7bd61ecc0c25632ece07554543cea94a85735e169a17532cac2a1c26df
font_01_sfnt_off000107ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012003.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12003 10596 bytes
SHA-256: 2f56ad769f6f8337cc14093c52aef927e57679d95820b4037e79a6f0dd2a5e0d