Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5ed136cfad1c1c5…

MALICIOUS

PDF

85.1 KB Created: 2021-09-12 21:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ba4ca641349e0829069b9e736b55dc62 SHA-1: 129aeea41099d3b7ecb2d0df5bc197732cc6dbcf SHA-256: a5ed136cfad1c1c507e9c55f1a2a45ba9ba5d358b374fad8f8b9514c4f8e6f95
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicative of a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites, potentially leveraging embedded JavaScript for obfuscation or further redirection.

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://stka.gr/ckfinder/userfiles/files/bededawajudejumow.pdf In PDF document text
    • https://speedwayinfo.hu/uploads/file/76007146429.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/a31e7a2917f6b09b1a0a26186d244c6d/30494707003.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021090411115473499.pdfIn PDF document text
    • http://unseretochter.ch/images/file/xutoxi.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/76982357693.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae5340b1ce---3749690443.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/67019916532.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/11782572638.pdfIn PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/54465327970.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/48362647529.pdfIn PDF document text
    • http://archiw.bibliotekalesmierz.eu/img/upload/files/34360681481.pdfIn PDF document text
    • https://sieuthimayphat.com/ckfinder/userfiles/files/29119772691.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161325687706e2---nipeva.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/1f812731d9a706d06964add11cc7d80b/64946919144.pdfIn PDF document text
    • http://moneymaker-gold.de/files/25598430118.pdfIn PDF document text
    • http://btsoft.vn/uploads/files/34999082973.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/fadf16574dd38336d1a9c4d93025b4af/52307662441.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/81625306451.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/97002502574.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/fobd92mnl8h8ehhm32k24660r6/24674907625.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=best+apk+sitesPDF 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_off0000e820.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE820 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010037.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10037 10020 bytes
SHA-256: 0e3dc225ce3e5d5de9e60db321a6166e48b92dde212684a766f5b0f3a7c7ca30
font_02_sfnt_off000116a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116A8 18300 bytes
SHA-256: abb8ed243b906dcde07879a0e9f49c40682ee18380945d2fd1f2342d33a1645e