Malicious PDF — malware analysis report

Static analysis result for SHA-256 87dcd740db0605e2…

MALICIOUS

PDF

74.5 KB Created: 2021-06-20 07:36:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 56b6cfd1d2b1d4073c6ad145da9d7e60 SHA-1: 667f3117e5cf3fd832b91972d04e77f72d74220d SHA-256: 87dcd740db0605e2c60d9eca8ac34508ed634f3222a2bdf168fa426c3148da4c
164 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to compromised WordPress sites, suggesting it is part of a link farm designed to distribute malware. The document body, though heavily obfuscated, appears to be a lure for 'periodic table flash cards', a common tactic to disguise malicious downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://wastran.ru/uplcv?utm_term=periodic+table+flash+cards+with+atomic+number+printable PDF link annotation
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0731df201---raguxuxosagovusefi.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/gidadivaxosofurarexit.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ba9f96c6d---96849663332.pdfIn PDF document text
    • http://karimeh.com/public/userfiles/file/96512799409.pdfIn PDF document text
    • https://bestcoloringpages.com/userfiles/file/xeradaduretupapov.pdfIn PDF document text
    • http://rld-carbon.ru/file/binavo.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/4153127719.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087de067915a---tatinij.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/dilerosekos.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e0c64531c---15680589093.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/kujawitalepoxaxovoronutip.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfacd43916---99825732246.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/70983039316.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/jegikufukadadomola.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/ca8551d86ccf3d16b3aa36b453426718/26243454041.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D1 6440 bytes
SHA-256: 629123bfde0685c5f69bbdd27ec008bde0224d5c30af1dabb990f6ee33ea778e
font_01_sfnt_off0000e4c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C5 5628 bytes
SHA-256: 0f1e7f90661ed66466596bbba84657eece8deb50eb3b84511c491cac2f7fcb88
font_02_sfnt_off0000f7ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7CA 10988 bytes
SHA-256: aa3a6f6bace1e9c156624a9561814ebc5db9fa347ff428ca0b34697cb8556791