Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1437d72423cf683…

MALICIOUS

PDF

73.0 KB Created: 2021-09-13 01:53:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3258a14c3d796427082bea98a9352b11 SHA-1: f03aa200d5f17a9e418957a046fcdbdb56b87557 SHA-256: f1437d72423cf6833ff335f61c448974334c8bba8b6cbb0dc5e7df6564785024
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to various domains, many of which are hosted on compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure itself appears to be a lure, with the document body being unreadable binary data, indicating it's not intended for user consumption but rather to exploit PDF vulnerabilities or redirect.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://www.miyadenthai.com/image/upload/File/mafimajogubixevovin.pdf In PDF document text
    • https://candica.pl/ckfinder/userfiles/files/13727587417.pdfIn PDF document text
    • http://ondamarinarest.com/upload/files/91162940664.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/2817015621.pdfIn PDF document text
    • https://carpenterstouchnj.supremeroi.com/FCKeditor/file/46324307560.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/pamixevijinuvar.pdfIn PDF document text
    • https://thegmsbihta.in/userfiles/file/62227716443.pdfIn PDF document text
    • https://marugame.hk/editor_upload/file/rowosajosu.pdfIn PDF document text
    • https://hoalavender.net/upload/files/minapazilajazenu.pdfIn PDF document text
    • http://coomargroup.com/ckfinder/userfiles/files/32157875734.pdfIn PDF document text
    • http://bike-aholic.com/UserFiles/file/84700954150.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/xixeradonufefizikore.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131ab59b66a4---sibosatisejazekizorofuvut.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/32931858560.pdfIn PDF document text
    • http://rainhouse.kr/data/editor/file/1083437309613a215b7f5f7.pdfIn PDF document text
    • http://cnsgawefgl.netsociality.com/upload/files/difibigejuminanofilej.pdfIn PDF document text
    • https://podimercrm.com/img/files/79473439463.pdfIn PDF document text
    • http://lt101shop.com/userfiles/files/98164105626.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210911003049_iofa4o.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/541e7fa3dfdface6a9dd4cf132b67312/32219172536.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///fegik.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/7ec0a9e65526c37dc9da508da8b48421/7267625659.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/99406280243.pdfIn PDF document text
    • http://isvpro.com/custom/files/66514488420.pdfIn PDF document text
    • https://tekartltd.com/upload/files/foxopafozigakesabop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=write+the+word+equation+for+respirationPDF 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_off0000bc61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC61 10876 bytes
SHA-256: a41b727dce312a641a010fc7f9b4543d449d563ba7bfebc731beac9d11a3524f
font_01_sfnt_off0000d549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD549 15892 bytes
SHA-256: 5e5e28e14e388e4786cafa4052ec49fec9550707268deeb7e792110131a09a93
font_02_sfnt_off0000fe63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1