Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bec722c8f51ff07…

MALICIOUS

PDF

84.2 KB Created: 2021-09-19 16:06:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 31f6f0415d7ba53509eba4a07421c689 SHA-1: 5933a98bca31e393eb2bbcccd3ff601b481c709a SHA-256: 8bec722c8f51ff07933aabc3ae2d507bd9c5b2989538ba57e5ec545e8e700838
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, some of which are associated with compromised CMS uploads. The embedded URLs and the document's structure suggest an attempt to trick users into visiting potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://gamboeng.com/assets/ckfinder/userfiles/files/sifuxusemotijaxam.pdf In PDF document text
    • http://recviem.ru/img/upload/58252933931.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/nugilenonusizobolura.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/batudusiruxuj.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/49983544783.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/40007555036.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139d999692e5---16528146534.pdfIn PDF document text
    • http://artanuji.ge/admin/ckeditor/ckfinder/userfiles/files/xurotejavigefofipimeru.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/pixapodama.pdfIn PDF document text
    • http://sziszolg.hu/editor_up/moxunalelarekifomeg.pdfIn PDF document text
    • https://nileagriculturalindustries.com/file/5497107639.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/wogawagaduzanakafelaj.pdfIn PDF document text
    • https://0900107678.com/upload/file/73900453004.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/c8991f3c0bec7e84b27d6ecd4d9a2fa2/vebuvirigujofasemimu.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/zujexolepipumigowegariw.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16141b31cd0f4b---kexakimavowexurukadig.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/40096968596.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/32764729440.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/xemusedumawafavada.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/26065386930.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+install+android+11+on+pixelPDF link annotation
    • https://mediaget.com/userfiles/files/melepase.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_off0000e097.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE097 10616 bytes
SHA-256: d9384b6f61e9d2b419f250e5cab05e0500cf9b8573e3f27468fa150593079653
font_01_sfnt_off0000f90c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF90C 19576 bytes
SHA-256: a84fd77420fd2f41514c816908f6a629c81860f91721534b4f28cd6d7d1774f1
font_02_sfnt_off00012ae4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1