Malicious PDF — malware analysis report

Static analysis result for SHA-256 55a82e23bda446ad…

MALICIOUS

PDF

74.9 KB Created: 2021-09-06 20:13:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 386bd13bec622c41df57483193312210 SHA-1: 8738f01ab4928a72a6f918a18dd5677720b49322 SHA-256: 55a82e23bda446adde9bbf244bb0e6e82a68bd444147969ec21081fd42717652
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF structure point towards an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/3e0d035517d050ef867053fb81b7f630/pezefedeza.pdf In PDF document text
    • http://sanga.asia/userData/board/file/sobexepepi.pdfIn PDF document text
    • http://grimastone.ru/files/46663275279.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa077b4540c---13709311661.pdfIn PDF document text
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/625a6ca6c99796ebde9c9f51471177bb/jekixi.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1609df08c19e34---fukoxiretulivusezovu.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/0e8e941c0c35882bdf8b8771028805c7/xizone.pdfIn PDF document text
    • http://dezmaster.com/userfiles/file/92332376354.pdfIn PDF document text
    • http://veribase.com/E/file/kizulasudozusofufu.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/94150629b57a95d337dfb7e6f03b1005/13255514351.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/48593600114.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/velexemolovumiwezilikali.pdfIn PDF document text
    • http://medrea.ru/upload/files/defagupuwisumuko.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/97b896ed23ee15af875eda4f460f561e/fifuvabotonugo.pdfIn PDF document text
    • http://360global.ca/userfiles/file/karozoxazi.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/fomelesafofumunolob.pdfIn PDF document text
    • http://rjt1.org/upload/files/60752515414.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607031d7099f3---rudobigodire.pdfIn PDF document text
    • https://pasarantogel2.com/contents//files/natipavodijimaf.pdfIn PDF document text
    • https://ols.lighting/wp-content/plugins/super-forms/uploads/php/files/cf8c9f7bd8c9d043b15b1a441e09e793/75109208308.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/521450979.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160774e406390e---bamewezefiwujiwakol.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/64188935556.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607df6b513192---romagikubigabivugexev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=measures+of+center+and+variability+worksheet+answersPDF 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_off0000c1bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1BB 11164 bytes
SHA-256: c93c9913d05f0b2a031b8b250aa7c57aabdefd8be42a80ffdad89c1321707d69
font_01_sfnt_off0000dbde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F0 16088 bytes
SHA-256: 723c51592d5e7178f8f42482d4fc58f5842bb9a31cc37a52eab5a44d921f8e39