Malicious PDF — malware analysis report

Static analysis result for SHA-256 77b2e939b11c3b45…

MALICIOUS

PDF

82.7 KB Created: 2021-09-21 00:13:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 55c1eae60d636e5b420d9bdcd6f82802 SHA-1: b095aa6daa058a2f0e84337a2629e4b0ef3d8778 SHA-256: 77b2e939b11c3b45e786fe886aa0f3a46c92267a42f407e95576dad870f8ebf5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and link farm patterns, suggesting it is designed to redirect users to compromised websites. The presence of embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further support the conclusion that this document is part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://inwebjor.ru/uplcv?utm_term=balloons+towers+defense+6 PDF link annotation
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130741f81365---56590483787.pdfIn PDF document text
    • https://mcdelandes.ca/uploads/file/76329718498.pdfIn PDF document text
    • http://pelesiuvalymas.lt/i/File/24600789359.pdfIn PDF document text
    • https://peptidturkiye.com/ckfinder/userfiles/files/4204748212.pdfIn PDF document text
    • https://www.ventisilva.com.br/ckfinder/userfiles/files/45752065977.pdfIn PDF document text
    • http://randygordonlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xinugexakixafutoxopanos.pdfIn PDF document text
    • https://suthuytinh.com/app/webroot/uploads/files/4692712267.pdfIn PDF document text
    • https://mmtours.si/uploads/gitefedixer.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/22331814838.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/55129342927.pdfIn PDF document text
    • http://edmo-cars.nl/images/file/6952397741.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/57327912204.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/17931432729.pdfIn PDF document text
    • https://consultemergingmarkets.cubsindia.com/files/wizaxuwewuribatosen.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f5665b24df---34177131345.pdfIn PDF document text
    • http://celesteandtorsten.wedding/images/file/pivimetadixoposumipawison.pdfIn PDF document text
    • https://aventura-agence.lu/userfiles/files/67131012648.pdfIn PDF document text
    • https://temahr.hr/files/titiwijopawadu.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/12632055669.pdfIn PDF document text
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/36069813910.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9158c94bf---23547469241.pdfIn PDF document text
    • http://geasit.it/userfiles/files/nupogekotewedojetanozir.pdfIn PDF document text
    • http://skupka23.ru/upload/m/vetimotinetebalugo.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA54 10560 bytes
SHA-256: 25ac8b5653f58a47199f38a38f9481e165ff969d330a679baa55e8d278a86ede
font_01_sfnt_off0000f2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BA 19212 bytes
SHA-256: fbdfd4d299b06ebde24b308f45a32b3e1cf9fa7f89f66cb75c8078bf8fc94a6a
font_02_sfnt_off00012544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12544 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1