Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6bd7428dfd842cd…

MALICIOUS

PDF

80.2 KB Created: 2021-09-14 05:48:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 72139921a7b4c8da80f78854cf59dc46 SHA-1: 9f4bf06c01abaa59a3d3f931a77d1c245f6a15d5 SHA-256: f6bd7428dfd842cd9191e57535ab177a1462dcfbf6684597692e29d0a4272af8
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to various domains. Several of these domains are associated with compromised CMS uploads or appear to be disposable hosting, suggesting an intent to distribute malicious content or conduct phishing. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a pattern of using such domains for link aggregation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://iva-vietnam.com/userfiles/file/1364678030.pdf In PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/desezabojidefefelo.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/f0c6bca4d1878b2d5447e78dd8a2aceb/85680514202.pdfIn PDF document text
    • https://allegypttours.net/userfiles/files/bedunuximoxezasuj.pdfIn PDF document text
    • http://bellamy.tw/uploads/files/202109140030149747.pdfIn PDF document text
    • http://www.greenfield-sustainability.com/images/files/jasavuvodinulofabumifuw.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/jusotasex.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/10761178272.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210907063058.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393860c3661---luximewu.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/wobekalezejigeposasin.pdfIn PDF document text
    • http://sinorarechem.com/upload/files/93834192750.pdfIn PDF document text
    • http://zhymwz.com/upfile/file/davoxunimak.pdfIn PDF document text
    • http://anninh247.info/upload/files/10711234876.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210909110032_gcc7wx.pdfIn PDF document text
    • http://touchpanelpro.com/upload/files/duzuwuzepezek.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/68383580471.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/68857282224.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/11984254507.pdfIn PDF document text
    • http://519pf.com/userfiles/files/8231154557.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378c383a484---jovorerozerikopigosoliza.pdfIn PDF document text
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/nerugasanavolib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=rush+racing+2+mod+apkPDF 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_off0000d115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD115 18912 bytes
SHA-256: 6c31e047f584835a379af56da25ef86cf49b8b2985467079c135bae661552901
font_01_sfnt_off0001024e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1024E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A65 11044 bytes
SHA-256: 663e3a71a5af30e90079aadc26967ca7b5a254261b8fc68ee46a9c6febbbabc4