Malicious PDF — malware analysis report

Static analysis result for SHA-256 637dfed76d5aaccb…

MALICIOUS

PDF

86.0 KB Created: 2021-09-16 21:19:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 548a89590a60cdb5efe2d097038007b1 SHA-1: 636345e4eb7ca8d612fed49ccdf5b195831a3a2b SHA-256: 637dfed76d5aaccb82f10517802158bb2cc3dbd196e77f997afdcb76af806932
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS uploads, indicative of a link farm designed to lure users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are common in spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/20165083422.pdf In PDF document text
    • https://bodzlomu.com/userfiles/file/32578268061.pdfIn PDF document text
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/kurigofidexivinebovomon.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c47a1b36f3---lewamitomeridogi.pdfIn PDF document text
    • https://mbbs.hr/files/koxikozinideboviwiluju.pdfIn PDF document text
    • http://ecilingirler.com/resimler/files/47431742812.pdfIn PDF document text
    • http://maskaevlawyer.ru/userfiles/file/89345395410.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021090516230497.pdfIn PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/nibomutaju.pdfIn PDF document text
    • http://dh-cell.net/ckfinder/userfiles/files/jesosiz.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/3547337ca8d3c2879a063c5d92208ee5/gujaretalejifupajepajebav.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613d58575c2c0---34040584801.pdfIn PDF document text
    • http://tradotel-riviera.com/file/dipetel.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/83007136168.pdfIn PDF document text
    • http://nhakhoauytinhaiphong.com/upload/files/jusanapopupuvuvakixaza.pdfIn PDF document text
    • http://izumrud38.com/ckfinder/userfiles/files/zoxijokuxaweraz.pdfIn PDF document text
    • http://onlinetradeshow.ir/uploads/files/varaxugewumek.pdfIn PDF document text
    • https://camerabentrenet.camerabentre.vn/ckfinder/userfiles/files/77473058156.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/42153428252.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/40492356909.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/44727141370.pdfIn PDF document text
    • https://qatarsecurityservices.com/public_html/userfiles/file/xavikawudedijazoluluri.pdfIn PDF document text
    • http://maybaobidinhdinh.com/upload/files/37984854261.pdfIn PDF document text
    • https://www.pharmawell.eu/ckfinder/userfiles/files/86825308322.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161377a52affbd---37953441209.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=dream+league+soccer+mod+unlimited+moneyPDF 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_off0000eb38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB38 17632 bytes
SHA-256: 3298910a9c6bd2b62e67c2b4b2210b1f890e6b244aff60c1f01c798d8a1b3dc7
font_01_sfnt_off0001191a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1191A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13131 10928 bytes
SHA-256: 2d1b60e9b6de894155e570aae354c790fdedae479979f99f0048070f16c313b4