Malicious PDF — malware analysis report

Static analysis result for SHA-256 4988ec56a63c4267…

MALICIOUS

PDF

112.7 KB Created: 2021-09-15 14:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81788db9cd3576415e01c7a1d2423633 SHA-1: 747c93f0ecdee8bf0e8785747b30f22c722a93f3 SHA-256: 4988ec56a63c4267a2f640f7a5eed6023ec134580b2841e2cac334fe89a096d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to distribute malicious content or conduct phishing. The presence of embedded URLs and the structure of the PDF, which appears to be generated by wkhtmltopdf, further support its use as a lure for malicious activities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327defeecd3---16474447484.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/2ba6443b6a3d4f143b0b97421be4ce81/29537295556.pdf
    • http://reylab.com/userfiles/file/50669956293.pdf
    • http://www.smwiarus.pl/ckfinder/userfiles/files/mivawotubexekogatoz.pdf
    • https://najlepsze-w-polsce.pl/uploads/minipezufixa.pdf
    • http://annabarons.lv/files/files/setejo.pdf
    • http://moiarchitekci.pl/pliki/file/37575580623.pdf
    • http://scbczy.cn/up_files/file/20210901_102801.pdf
    • http://ngocphuocjsc.com/public/default/ckeditor/files/33715453425.pdf
    • https://searchkar.com/ci/userfiles/files/42617090884.pdf
    • https://newdesert.pl/userfiles/file/9313747020.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/627d2ea0d92f7de70106cb9c7a0053d6/miwovatuzadaborodoket.pdf
    • https://www.edm-medical.net/ckfinder/userfiles/files/85737748323.pdf
    • http://xz-brand.com/ckfinder/userfiles/files/97626448113.pdf
    • http://highspiritsmusic.com/ckfinder/userfiles/files/61968229987.pdf
    • https://sd-olimp.hr/files/4072870769.pdf
    • https://pasifikendustriyel.com/userfiles/file/vazap.pdf
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/1b6eaa3353fc4c65aabc870f4e1e9843/dupibodevugivuxinimesafe.pdf
    • https://akconta.com/uploads/files/sakonosebutilamok.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed3e672ff1---86822684736.pdf
    • http://nanoscopy.ru/uploads/files/60973970726.pdf
    • http://whatifitspossible.com/ckfinder/userfiles/files/32821253741.pdf
    • http://vdavloeren.be/userfiles/files/66314063314.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=b+tech+movie+online+watch+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015023.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15023 16792 bytes
font_01_sfnt_off0001683a.bin
5414f59a419b184878cbc3cf3299fc9c86f956e1cd323c7ec8f801de4c3fb50f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1683A 10636 bytes
font_02_sfnt_off0001806f.bin
a7c0a62271b53a2afeaa6c658eff2688feb2c5ae8cce8481070b6356775394de
pdf-font-stream PDF embedded font (sfnt) at offset 0x1806F 20148 bytes