Malicious PDF — malware analysis report

Static analysis result for SHA-256 5dde0bff1e3a9439…

MALICIOUS

PDF

71.2 KB Created: 2021-09-16 17:24:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 13ae27ddb5a9fba6dd6d27b3c6f88544 SHA-1: b6f2b971e273e18922b00e7c28af8fce8c8be9cc SHA-256: 5dde0bff1e3a9439e6204900b50103ab3acd59a292c5337a5e9210dabfa4f393
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm with numerous URLs pointing to unknown PDF files hosted on potentially compromised or disposable domains. Heuristics indicate these are non-clustered link farms on disposable hosting, and one URL points to a compromised WordPress upload. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://anhuizpyy.com/upload_fck/file/2021-9-8/20210908225656268018.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613522875c4c6---buxufabakadulidubojejixig.pdfIn PDF document text
    • https://durimawar.com/contents/files/3398937207.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/neged.pdfIn PDF document text
    • http://iranjobex.com/cache/fck_files/file/bexonapori.pdfIn PDF document text
    • http://vibrator4you.cz/UserFiles/File/43827291693.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/f5258c7ce7c547ecd4c7cc640c4022cf/88216126517.pdfIn PDF document text
    • http://cmtsport.com/pliki/56551005282.pdfIn PDF document text
    • http://playoz.com/ckfinder/userfiles/files/faresi.pdfIn PDF document text
    • https://digireg.sk/upload/4380486286.pdfIn PDF document text
    • http://ltmetal.com/userfiles/files/58740030436.pdfIn PDF document text
    • http://salwex.hu/file/gijogavuz.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/direl.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/somalogede.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/97106835835.pdfIn PDF document text
    • http://style4.allwebeasy.com/userfiles/files/70094862366.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/59355152909.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/3ffed444f6173acf98056606e0a0bc32/3286509467.pdfIn PDF document text
    • https://thebottombillion.org/business_school/uploads/file/2982729490.pdfIn PDF document text
    • https://beta.nhatthiengroup.com/files/uploaded/files/63873522056.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/2160335948.pdfIn PDF document text
    • https://accidentmatters.com/ckfinder/userfiles/files/90262831222.pdfIn PDF document text
    • https://www.disbel.es/ckfinder/userfiles/files/vezupalokiwujirigogular.pdfIn PDF document text
    • http://parikshitconstruction.com/uploads/61138471198.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=fransiplus+sign+inPDF 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_off0000b797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB797 10156 bytes
SHA-256: f379c1d34715f8eb88a8977d202333c79fd467797072ed0ecc1e6556a4d509b8
font_01_sfnt_off0000ce49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e65b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65B 15704 bytes
SHA-256: 37904a6e58a51663e95994fa467c4c0857bec3058d4eee5e3af62381f4994ed8