Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb66e0b215c674e1…

MALICIOUS

PDF

83.3 KB Created: 2021-09-19 00:38:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 209885afd66ef0a01cef4b0d06e36795 SHA-1: 146b3484d8d729d6c9200c84763bbe1bc50f37c8 SHA-256: fb66e0b215c674e117327e8b9e80fd245ea9fa4b22bae1c77bd312f11275f800
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload storage, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9762

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://miwon.com.vn/app/webroot/uploads/files/90381163607.pdf
    • https://5of7edwardstreet.com/assets/media/files/25002063354.pdf
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/xabujaladeruwu.pdf
    • http://eska-lift.ru/userfiles/file/65821381007.pdf
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/gokax.pdf
    • http://wxbeimei.cn/upload/ckimg/files/202109062129271913.pdf
    • https://hinaweb.com/upload/file/dakabirajukowifutow.pdf
    • http://santehnika34.ru/images/file/dilelazagod.pdf
    • http://carrasvilla.es/uploads/files/94684691667.pdf
    • https://studiopros.com/userfiles/file/
    • http://ohmamakitchen.com/uploads/files/ginirezutata.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/nketrfj4ikpr9ogslj2heotdk7/lefozaj.pdf
    • http://serting.eu/userfiles/files/37770506954.pdf
    • http://ohdiabo.net/images/ckeditor/files/wasajeruxumuvuvim.pdf
    • http://rivebistro.net/ckfinder/userfiles/files/55180582249.pdf
    • http://jlsxjy.com/right/UploadFile/file///2021091117181173499.pdf
    • http://scuderieverdina.it/scuderia/userfiles/file/pudefil.pdf
    • http://seghers.kr/data/editor/file/1413239921613c7b4c39106.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407efe5c798---45103867579.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/f5829d483471fbc2a16945ff648eb9d0/57267466780.pdf
    • https://pustelnik-budownictwo.pl/ckfinder/userfiles/files/29362940299.pdf
    • http://appartementslisa.it/an3_Uploads/file/4002872817.pdf
    • http://aktifithalat.com/resimlerfiles/89492114400.pdf
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/mebotavozibubofuvevadewix.pdf
    • http://sinproval.it/userfiles/files/53813121197.pdf
    • https://baoyi-chuck.com/ckfinder/userfiles/files/91182960741.pdf
    • https://metrosecuritynepal.com/assets/userfiles/files/9251800631.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=poweramp+full+version+unlocker+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d21c.bin
6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xD21C 1680 bytes
font_01_sfnt_off0000da14.bin
3cc11921a13521743fd2711bbed0611c869f2f01bbb4c869f27a06ca36796507
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA14 19548 bytes
font_02_sfnt_off00010d51.bin
165243141c6864e9a03cd6b4afee4cfca1001308d46688adb1eb75e10a63951b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D51 10888 bytes
font_03_sfnt_off00012690.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12690 16792 bytes