Malicious PDF — malware analysis report

Static analysis result for SHA-256 81eb19fb815b90b1…

MALICIOUS

PDF

89.7 KB Created: 2021-06-27 07:41:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 396ec96c3ba847055c1eb0a1296652cc SHA-1: fae438db1682af6f67b16d05e5ec331c878148ba SHA-256: 81eb19fb815b90b17a37e109523ddce13d3ef7e339303847d2015d90f310788e
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous external links, many hosted on compromised WordPress sites, suggesting it functions as a link farm to direct users to malicious content. The presence of embedded URLs and the overall structure point towards an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://laborke.ru/uplcv?utm_term=choosing+a+mortar+and+pestle
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607d475f74733---63515216481.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/0ccb5a4d9e134fade308a667eb327a9a/28149431089.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607052e1a7494---78291203606.pdf
    • https://questyme.com/userfiles/file/25543229770.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1609bbcd9d2e4b---datidubodepegonujuji.pdf
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609005d054f73---48915374897.pdf
    • http://htwy.com/upload/file/kexinofifo.pdf
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/53398be56bca3657cfd1f127be5c8af5/votekixuxubenalit.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a4e22826294---vusekazonis.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d1c6770ba46---kapubiri.pdf
    • http://maytinhtuyenquang.com/home/maytinhtuy/domains/maytinhtuyenquang.com/public_html/images/file/44650230871.pdf
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/74836308098.pdf
    • https://bharatbiodiesel.com/userfiles/file/75878571731.pdf
    • http://sicompk.com/survey/userfiles/files/24430003062.pdf
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb00c79b9a---39025318030.pdf
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/2de7654c201c8287a5d8d20c78448bf7/wipumafajarikawa.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/f5ea6c1ddb04d4b259e014a56af2ce05/5926065626.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/06b88640e9ffc78c37d95d7e730f5eae/muruxobepusene.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160c0d5761e847---lupazununa.pdf
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/2dcae066a0ad6f4daa86b25ebb6a0c10/61657712908.pdf
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b29d0db837a---89981507753.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa9b.bin
762d4b142933f99142d8b240040e9039ab79136cf495dd6512fdb51ce7fd251c
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA9B 17328 bytes
font_01_sfnt_off00012784.bin
0b6eb18433ed6da4ea6d97e2d28074445f8f456621982b952578248292ba666b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12784 10868 bytes
font_02_sfnt_off00014043.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14043 16792 bytes