Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4e57a249bb8d0b…

MALICIOUS

PDF

84.9 KB Created: 2021-09-18 12:15:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 001dda34edd0ae7421baf11582f185c0 SHA-1: 37c9875a83bcda8951b02e777d97eaa7ca2d083c SHA-256: 8d4e57a249bb8d0bbb4e2fcf0e4f92eec025860dd62ca3f285d9b55702ef3c68
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, hosting numerous PDF files on compromised websites, likely for SEO poisoning or to distribute further malware. The embedded URLs point to various compromised WordPress sites, indicating a broad distribution effort.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/baccd263fc90b7dd1fa987a987f21ca4/85379536620.pdf In PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613b245f5ddbe---86080588302.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/4a2f6abe4f03e39f4b646f536c85656e/94687168815.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/g07cbd6altt8id0dqhf14oqdas/31781180062.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/losemogoj.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/d50c3be59d8e7f5d399032495ffb0ac0/64908994866.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/vubixogejofupir.pdfIn PDF document text
    • http://heizler.hu/files/file/34754119525.pdfIn PDF document text
    • http://torremaggiore.sitmap.it/files/files/31990695189.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/8816295114.pdfIn PDF document text
    • https://magazinul-de-instalatii-sanitare.ro/app/webroot/files/userfiles/files/dazemomuzagapuj.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16134b7bcdf02c---50237975375.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/rpb8ar1ee7k279f5bjsiq942hr/5170073134.pdfIn PDF document text
    • http://kavernoklub.com/campannas/file/18346048532.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/xobunawulase.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/pegivodekumagitujabosu.pdfIn PDF document text
    • http://1544-7419.net/upload/fckeditor/file/48245349804.pdfIn PDF document text
    • https://camelcarpet.org/d/files/lavudimakerikizurogilewi.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/jomavojukirenofukal.pdfIn PDF document text
    • https://sanvexe.vn/webroot/img/files/dabezeboditub.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/netebisojevotekavusese.pdfIn PDF document text
    • http://jca-t.com/fck_image/file/55242489489.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/25627275412.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=world+number+one+game+for+androidPDF 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_off0000e843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE843 17472 bytes
SHA-256: 482fbb500d600748168a95611e663acea90ffd2b2e367ecbf10cf303e2d8872a
font_01_sfnt_off00011568.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11568 10664 bytes
SHA-256: 5aef19ba803b35e828656dbf14244210f4213378b0d8f8b2ffbc105485d340ac
font_02_sfnt_off00012d8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1