Malicious PDF — malware analysis report

Static analysis result for SHA-256 41ac4561917efe74…

MALICIOUS

PDF

82.6 KB Created: 2021-09-20 07:10:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 85649f86ef6f528b0bae58a7a6e93e54 SHA-1: 451fb250b4b4d66e6f7c51c45c23b92cd9f887e1 SHA-256: 41ac4561917efe743b11d8ba9530bde494236ed3210809b432ef615478dff6ca
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm on disposable hosting, likely to trick users into downloading further malware. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics suggest an attempt to deliver a payload, potentially via JavaScript execution within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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.biosafety.biz/ckfinder/userfiles/files/84921831437.pdf In PDF document text
    • https://czus-lukasa.sk/userfiles/file/jinomabovajaw.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/dewobuzebulanipanujileziw.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347f6f68a21---mikisepete.pdfIn PDF document text
    • http://www.moyekolodin.com/files/futemuvozulodavope.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/98530519606.pdfIn PDF document text
    • http://jljemc.com/upload/files/gapilojepuwo.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/worijovivutakalirewawa.pdfIn PDF document text
    • https://granitnet.hu/editor_up/94856248549.pdfIn PDF document text
    • http://thegioimercedes.com/upload/files/togipomuzezapifutawawulax.pdfIn PDF document text
    • http://spain-ex.com/images/blog/file/36847105495.pdfIn PDF document text
    • https://veaodaibrahma.com/uploads/image/files/97088361148.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/49690193415.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/motinebigi.pdfIn PDF document text
    • https://ribaczpeter.hu/files/file/fikizi.pdfIn PDF document text
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/34064895566.pdfIn PDF document text
    • http://dgone.kr/userfiles/file/20210919185756.pdfIn PDF document text
    • http://ng-sons.com/userfiles/file/96011189670.pdfIn PDF document text
    • https://axlthailand.com/imagexx/files/58813840338.pdfIn PDF document text
    • http://avandcie-automation.fr/ckfinder/userfiles/files/kikuvebutukagorabe.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/46200809449.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/zebusoronejozori.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/nusezurajazafemumafeke.pdfIn PDF document text
    • http://geyuping.com/geyuping/uploadfile/file/2021091400233873499.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/q91323pg6d4vqgds81e6pqs1f5/tifenodujuwelepof.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/xaruzizusig.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/48320438187.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+set+location+on+android+phonePDF 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_off0000de01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE01 17764 bytes
SHA-256: 3a3768f9503390d62afcebdbb141ad23e917ba4c0e35c88a7419c4399b3cece2
font_01_sfnt_off00010bfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12415 10688 bytes
SHA-256: f27e54fc31e9ef4e56772da06aea30e12ff721b6564ceaec5d363e695095424f