Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1870d4ec689b760…

MALICIOUS

PDF

127.4 KB Created: 2021-09-07 21:29:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a92cba6c23f17ead1edb586cb3a31063 SHA-1: f4738f61eaa503512db4c45f6a20f0931dcbca75 SHA-256: b1870d4ec689b76055348f13f446262bd1762fed8a88417adb6582da08dec1c6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised CMS upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9741

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://crysiq.ru/uplcv?utm_term=bacterial+genome+sequencing+pdf PDF link annotation
    • https://gujaratisamajparis.org/upload/files/xinabilon.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/97214191865.pdfIn PDF document text
    • http://savitapiti.org/ckfinder/userfiles/files/82813394021.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///xulebomodinivolazan.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff3dd2b999---57995036506.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/2b1a74bfcf6eabba49c1f9ec9219e960/kiziwaperevajuvepilu.pdfIn PDF document text
    • http://backyardreleaf.ca/clients/6/6a/6a4eaaf8452764cb6fc14c9064ed0c71/File/texegalimovunusipebe.pdfIn PDF document text
    • https://parfumzone.ro/files/file/febilejineveradagi.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/84722275902.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/voketazejedixuxam.pdfIn PDF document text
    • http://montazerangroup.com/uploader/file/janiwenijabuzagupupumeti.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abb6b777d2e---witizegurowazunasabikowol.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/4cq5k8ccnjclt73583qe92ngqt/9375226483.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/59845267483.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/7ca8f2b484ec4cb1f725d56fab635411/keritafegulenekuvaxuv.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/41777516537.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/mikunagexivurebape.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608e60ae800f6---5640352786.pdfIn PDF document text
    • http://ldbell1965.net/clients/85689/File/13320387547.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/5452545944.pdfIn PDF document text
    • http://clarasonic.com/upload/file/xajatofutapaxed.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/f6839e1abf34b734e2477d820dbf19b5/28918400426.pdfIn PDF document text
    • http://nakatka.com/files/file/gepinobiwurudi.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160763b15ce694---gimupapusomedevifetorituf.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/88499477519.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/mjh3jt69k0dflgi7snaloi84a3/7927875421.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017080.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17080 11264 bytes
SHA-256: 31c85dc14f5ecd66877c4c65f5e35134516e67e3b5d5f30a487b967ab23fcced
font_01_sfnt_off00018a66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A66 16344 bytes
SHA-256: 956dcfb6e4b364945778dec33c3f5ac6ddb698c9e31bee75f05292afdf71421c
font_02_sfnt_off0001a09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A09A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off0001b8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B8AC 20788 bytes
SHA-256: eda8349615e6d91de1f8c4c757f45ce61516ebe07e3e2d9393c69782bfeef87e