Malicious PDF — malware analysis report

Static analysis result for SHA-256 0fe814381d16fc49…

MALICIOUS

PDF

72.7 KB Created: 2021-05-31 07:14:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 086fcbe6c43c9696342f37a887949d28 SHA-1: f51f8534e71d59950fe6f2268ebbe9b4d30e33cc SHA-256: 0fe814381d16fc49cd6513216a6a0b8ceaa8c441c422c7e4e97963e8f38ab1ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, contains metadata related to 'wkhtmltopdf' and a Spanish language textbook title, which may be used to disguise the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/68376d4885d8fb5e5abe3c21bf3d9208/299260008.pdf In PDF document text
    • http://albino-pitti.com/pub_img/file/bojapavojonopiseleza.pdfIn PDF document text
    • https://olterus.com/contents//files/64081840473.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16078a0c63918e---99250976878.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4432889448---nevonosaxadivukefepupogo.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/svf8b4gdun222ulph1ima7pjd6/96316358181.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/79884878916.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/idqc5utu189cl0pkn0mjdvfvr4/dofimemitolodomaxonesejat.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/ei779v5ro5f8bk7526nv0ei0u7/18284862615.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/905502f715f075cc63a9743f626ce885/71812769923.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7712e7910c---18906959502.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608f747cd854c---91818803784.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/c76784ba338425cfa0ccd58dd0369c32/gudixarawofofixekejulu.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/iaslv6pqk249u7dkp4l0revsd4/zakobumaga.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/443fbcc6ef5ac403e6aab87b1faaf826/86818954916.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=libro+de+lengua+castellana+y+literatura+2+eso+casalsPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF9E 5304 bytes
SHA-256: 28a518aa69369c8decfd9687588841a37f465ce5aac1c98fd17f0df9825b6413
font_01_sfnt_off0000e1b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B5 11072 bytes
SHA-256: d2f28c5cf3ed5f8a58a1b74c3319ba11174ee693404e5bd73ca4dd4ad9fa26a0
font_02_sfnt_off00010561.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10561 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176