Malicious PDF — malware analysis report

Static analysis result for SHA-256 18d140cf80868586…

MALICIOUS

PDF

86.6 KB Created: 2021-08-03 18:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 4c4cf9c727e32675600eb46c5193d634 SHA-1: 136d69182b0aab420551af6eaf62b7a8e2d8ab7f SHA-256: 18d140cf808685863b501c7518ba73b7e1b6f02f2fe5be5b4f0e6a919b00fa03
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and a machine learning classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage and other disposable hosting sites. While no scripts were explicitly extracted, the nature of the link farm suggests it is designed to lead users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://robertbah.si/files/file/84769975511.pdf In PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc916d1776---39915263782.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/832aac9cbbc58b4bfc1ea831e1b2af9c/tujewipepuvawuxunokivew.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/625a803139ee18b0f558006e7cfd12f6/nupakerobetoka.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/o7eietriv0p2e03rk0kudf58uh/72593320730.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a7ab7cd0f---55093450925.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/edbc9aa810b37775c8eed04fa490044e/64038095146.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/oqbs6jhuucpvldta32q8nait46/39482058245.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/9du87c96af6d14ua2ansv8lman/81857444811.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/addi9uhu9he2chbrsvlim60upr/kogoboxikiboniravadadage.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/d9b4b40f3c5a0f8d8c32fdbd398903fc/zitupuzazewot.pdfIn PDF document text
    • https://soechi.id/userfiles/file/97283280048.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608ee9ee2313b---10956092606.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021715221133.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/d09ec3dbf497fb743af2afb9a66c6a57/divajure.pdfIn PDF document text
    • https://kawanmto.net/contents//files/laxuxu.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/2dq0c5g4o7oe0uo3v347od1qp8/77052702030.pdfIn PDF document text
    • http://portalkucharski.pl/app/webroot/media/files/14737768128.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/nimijokigituwebakopega.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/f48357088e8985ada6379666569f94da/konakavirewomefexikowos.pdfIn PDF document text
    • http://globeksa.com/ckfinder/userfiles/files/2011573304.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16082e9cc12963---51324607309.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/62498682836.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/rufaxalunejepezilodik.pdfIn PDF document text
    • https://qualitymattressfactory.com/admin/userfiles/file/13077739473.pdfIn PDF document text
    • http://dietmoiquangle.com/webroot/img/files/resalapuzetudajigikinenu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=differential+equations+with+boundary+value+problems+%282nd+edition%29+pdf+downloadPDF 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_off0000db9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AD 28948 bytes
SHA-256: 55bb45e66f41cded0e4388201bd26e7d4231b1669c7660271522743041c1f018
font_02_sfnt_off00012d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D1C 11692 bytes
SHA-256: fcc9820660006b30ae81118306c44764d19f6553a7c666a37ba198f6f13a9f0b