Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8841f2e9a21f252…

MALICIOUS

PDF

84.6 KB Created: 2021-10-18 02:04:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c43d11d95b34220b5386eb8d3de09385 SHA-1: 9b3e5265ee39cbdeff27b761478cc8ca1b48ef65 SHA-256: b8841f2e9a21f252590cd36444da46684f2bd3b3c79c35cf86a59488511086eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or malware distribution intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oniceh.ru/uplcv?utm_term=drinking+milk+after+dinner+is+good+or+bad PDF link annotation
    • http://hanauhrova.cz/files/59423021081.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/fibaliwarizelirejor.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/e3ded221592e4bc0e839ebbd819f9d9a/mamudujebojekakuvulawiri.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615b08acf2f93---zibugoxawojixasaxejaleza.pdfIn PDF document text
    • http://p-energo.ru/content/file/72565190579.pdfIn PDF document text
    • http://aromaonly1.com/yamituki-n/uploads/files/jitovebovojaxabelapizudin.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/gpsom08edc4vgbai55i0haudle/79618965450.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/9cdcd3bc770a3b8d7ab0c88954067477/85415957912.pdfIn PDF document text
    • http://bridgestone-ice-cruiser-7000.ru/ckfinder/userfiles/files/firini.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/2279261274.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109121911093641.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/gokomu.pdfIn PDF document text
    • http://sitarofindiamd.com/userfiles/file/6635749753.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/d8e16b02dd3dc3fd2833dd220d420210/71057505922.pdfIn PDF document text
    • http://asbu.net/uploads/FCK_files/file/42865419720.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/file/87159973036.pdfIn PDF document text
    • http://traktor-tv.de/sites/default/files/file/69428527465.pdfIn PDF document text
    • http://aven.su/userfiles/file/lunezorajuzamekon.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/tagebaso.pdfIn PDF document text
    • http://hzosm.com/images/upload/File/16258977804.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615ebeebd1a7a---48391425833.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_off0000e673.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE673 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE8A 10932 bytes
SHA-256: 24fb6189582d30cd84e3730f370d4a826fd94166e7d62a1f3f4505a5ce979e08
font_02_sfnt_off0001179c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1179C 17908 bytes
SHA-256: d8abe32f45cccf483bc35fea709baf3bb8e11b1b1b0b722241dad8117ba5b034