Malicious PDF — malware analysis report

Static analysis result for SHA-256 91845451a3734fc2…

MALICIOUS

PDF

71.7 KB Created: 2021-08-26 01:55:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 2a595af2148904aaeb0ef2b5a0bf3a8a SHA-1: 93515187ce268e365fbce4d505a0894dbbbcabc9 SHA-256: 91845451a3734fc27b098dd8124d09941c8c5ac94939ce37770da7df618be3c7
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs and link farm characteristics indicate a phishing or malware distribution attempt, likely delivered as a spearphishing attachment. The document's structure suggests it is designed to redirect users to compromised WordPress uploads and other disposable hosting sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9945

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://allytemp.ru/uplcv?utm_term=orthostatic+hypotension+in+young+adults PDF link annotation
    • http://xinghui.co/upload/ckimg/files/202108211023336132.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/1b2c017e7de8894019777be9d2ddeb7a/51216069459.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/fifosebavakader.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/jukose.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/80eeb14b8bd71d82ad93ae85d1cc869c/13051921698.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/90045579240.pdfIn PDF document text
    • http://ekopaczka.pl/imgbrama/files/bovazobenopumam.pdfIn PDF document text
    • http://kuppersbusch-center.ru/uploads/files/vegibinoretodosotogexogo.pdfIn PDF document text
    • http://livingkaneohe.com/userimages/33864825514.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/89851346832.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160948480cbb36---92853374272.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/or6ovkjfv3c9qgrnmk8gjbjoed/patedarewezuxejaw.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/43d8e59d86de2b09d4a9b7b3300612cb/busiwanadivun.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609658260d462---jidel.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/894afa559c5d7fb6bd4ae9623bca449d/bozatuxoviju.pdfIn PDF document text
    • http://iphysiology.ru/upload/88084980819.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/3284290445.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d15beec89c---moxotu.pdfIn PDF document text
    • https://hanyauntuktesting.com/contents//files/18075413245.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/beribiwiza.pdfIn PDF document text
    • http://aimic.com/userfiles/file/zilamidanopulikotukow.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072758b25fd3---xuvepujej.pdfIn PDF document text
    • https://wyslijpaczki.pl/app/webroot/files/userfiles/file/gobobujema.pdfIn PDF document text
    • https://multimetrics.com/ckfinder/userfiles/files/mafomowaniwafogetizufapu.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/77567264336.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/31399092304.pdfIn PDF document text
    • http://barcelonasixtytwo.com/userfiles/file/rufanaxibudanu.pdfIn PDF document text
    • 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_off0000bb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d397.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD397 13996 bytes
SHA-256: 93db092d9651e9a2bfbd934af3b7115ac640070d336bbd2286fad9a7336a4be5
font_02_sfnt_off0000f65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65D 11032 bytes
SHA-256: 255517b1ac634619906999a8e014a39ba6f0b1dd26557d13c2b37bbb15aca162