Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf3981349f090a37…

MALICIOUS

PDF

74.4 KB Created: 2021-09-26 18:33:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 7a9d3618dd3ca9656e8cb60297615631 SHA-1: 723f26dbf84d50b0703c838a59c7526f23f6cb70 SHA-256: bf3981349f090a37bcc32c6bf8663af0df38eec45e8a2d4c596193155b4d4e0f
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings strongly suggests the document's purpose is to redirect users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drigungkagyurinchenpalbarling.org/upload/userfiles/files/41376840042.pdf In PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/29563555749.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/60192080849.pdfIn PDF document text
    • https://zlato-stribro-investice.com/upload/files/40710578047.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/007f23a12d02d51255fdb94be5581aeb.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/99500061179.pdfIn PDF document text
    • https://cv-vezouze.fr/media/file/xesemefukimezijagobe.pdfIn PDF document text
    • http://wellgroup.cz/UserFiles/File/fowasadaregodepule.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/wopepaxewu.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6873c9c8b---19178616974.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614c80915c816---morolapadefipivijon.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/78130284792.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210920082555.pdfIn PDF document text
    • http://mvpbuilding.com/userfiles/file/38111793792.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210901121240960257070.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/06i6uvn9ns8c52ce6kaq9jm98c/70827133658.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/161309e7745a60---2277177545.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/bomuvaloguzagir.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/bepodenududalukewujemuzul.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/lolivenigituf.pdfIn PDF document text
    • https://10s317.com/uploads/files/202109182036063569.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/tuginixetoro.pdfIn PDF document text
    • http://karate-talence.com/newsite/userfiles/files/kinanizelaninufovawu.pdfIn PDF document text
    • http://rockbond-aac.com/id-admin/fckImages/file/40279262486.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=mobisaver+for+android+fullPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bd1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD1A 17832 bytes
SHA-256: 07c8270ccd7842b38768e1b0a40de9fc6ad6a9b88c949b622e4a1dd49b6f2a58
font_01_sfnt_off0000eb8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB8A 10548 bytes
SHA-256: b21a6c7849b4d3bce3b6742ca59715b567ce729470157a92da3b6a2f907a9e10
font_02_sfnt_off000103b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1