Malicious PDF — malware analysis report

Static analysis result for SHA-256 38661b68c01679ba…

MALICIOUS

PDF

73.4 KB Created: 2021-05-03 18:08:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 8d7f59ea1046547dca73723f9cee2959 SHA-1: b2c7b731e25336bd900e52bfdd1603cc2e6de76b SHA-256: 38661b68c01679bacaea86b4055128b026d13eceed27b3b0f8ff115269c67406
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing lure. It contains a link farm pointing to compromised CMS upload storage, suggesting an attempt to distribute further malicious content. The document body, though heavily obfuscated, appears to be a lure for 'aptitude test questions and answers'. No scripts were extracted, but the presence of numerous embedded URLs and the link farm structure indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607231b62ff4c---53882732176.pdf In PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606de6930818f---gevuzemoxeraxirebakusaxob.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/rpeloc1l070fn1qsoc6rcvd0t4/11253728864.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9044430cd---rilafuvoguk.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607151505c32b---81516550843.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/044b34447910f86ea8c451254e087bf1/movetawafukirazedulatesub.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/bqfkc2n0ot5m07792hqqu6054a/40280074857.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/138d93ee2280b536fa9b0806a114503d/17343757409.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-3/20210503072431402420.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/ed3bdab35dee0cbca9183d386d8f4c51/38447640054.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/2ac04c9847993b0e9471bac11aa1b9f7/venikopatanabutinefu.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608430a826a30---45961054575.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/xisefifoda.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5d3861666---pojoxadajozomulam.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=ey+aptitude+test+questions+and+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1AC 5200 bytes
SHA-256: f4e966e98c7d02ce96a99fde425a6c0800c19bdc6797e31cf550a704d7f22b5b
font_01_sfnt_off0000f37f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37F 10984 bytes
SHA-256: e0e7f20fb36aa782372891b6887711ff1ff5aa474ca8d37a5fafcf5649bca30d