Malicious PDF — malware analysis report

Static analysis result for SHA-256 25c81f58688e17c0…

MALICIOUS

PDF

80.4 KB Created: 2021-10-09 06:59:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d8b3dc11d6ef04184c18585ce7cec3c5 SHA-1: 3f43616a44d0ac730f62a4a63493a0287e1b3197 SHA-256: 25c81f58688e17c0aaef9c087a1d4e3a3ba24b20a293c615c35f22fa37c55f4a
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple websites, with several hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wawabed.pl/uploads/userfiles/file/61274477084.pdf In PDF document text
    • https://netlandschool.cl/files/33535138933.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/5fjk04fd23e9nmnk4mls7g3p65/23848013989.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/7g97o349ml81sgf5b4b6uo5ri6/lopifiso.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/mopajuki.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/95140503935.pdfIn PDF document text
    • http://huefpdf.org/upload/file/17690259172.pdfIn PDF document text
    • http://zhuoer.ltd/userfiles/file/88881774742.pdfIn PDF document text
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/bimabefetozazoba.pdfIn PDF document text
    • https://at1apigroup3.com/contents/files/95639886941.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/09e245a9fac1126238640aa3095e082f/mebuzitujomewovidef.pdfIn PDF document text
    • http://autohondl.cz/userfiles/file/refajiwafemesuzegiz.pdfIn PDF document text
    • http://chaitraglaze.com/uploads/81341007881.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/qpp8ssa4ta42n371tfhjrrrsl8/femos.pdfIn PDF document text
    • https://renewone.de/files/veramemizikuwur.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615cfd44b7b0c---92374365084.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353c5e38d2e---bafepanumavufugugusiruje.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/55320592714.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/161567a9567a6c---nelexix.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/2021918556496627.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615df3b4061e9---zomuzexawavupuxibuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=grilled+burger+near+mePDF 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_off0000d133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD133 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE945 19960 bytes
SHA-256: 1a040281d5f5ad5ec814a5edd5c96c0992d1c38dd8a1b6847d79a6cd43b67290
font_02_sfnt_off00011c87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C87 10484 bytes
SHA-256: 8124839167346f07f360ed7a17a7c5a7f3a541299d0ea5dadafcc9eab7d137eb