Malicious PDF — malware analysis report

Static analysis result for SHA-256 f18de7f2f34b1390…

MALICIOUS

PDF

83.4 KB Created: 2021-09-08 18:17:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e7590d52dca5290c63f0cdf15d5f9604 SHA-1: 8e90b63650bafb1b3e3f091026891735757e5f37 SHA-256: f18de7f2f34b1390c2d2e777e5957aa9ed6238e98118174e3a99084a5b8f2ccb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains numerous external links, many of which point to compromised WordPress sites or are part of a link farm designed to manipulate search engine results. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://crysiq.ru/uplcv?utm_term=trastornos+psicologicos+en+adolescentes+pdf PDF link annotation
    • http://cadelupo.it/userfiles/files/20783597307.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/davupuzijexabobi.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/bofon.pdfIn PDF document text
    • http://ssp.by/var/upload/30354582625.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/90ed03defa4240c8b119e6399fffc060/53173075098.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/55572591900.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/44250373328.pdfIn PDF document text
    • http://emilybarnes.com/DEVELOPMENT/VERSIONED/emilybarnes/trunk/sites/default/files/file/26453566735.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/17719875023.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/b0aef5e9479eec3a77b7897bd866d384/xifozobibev.pdfIn PDF document text
    • http://atel-j.nl/uploads/files/35649044557.pdfIn PDF document text
    • http://internet-trade.cz/UserFiles/file/30835994812.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/41593944974.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/65740025940.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/83659607978.pdfIn PDF document text
    • https://bnovum.hu/downloads/vaxasituxof.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/jubetenibitamo.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/zofifokej.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/aaacd7e394849d5d9f5b14654664a180/35694388025.pdfIn PDF document text
    • http://ranch.pl/files/file/punosadonuzepis.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/xavumazaxin.pdfIn PDF document text
    • http://bulmarconsult.com/files/xopugusagi.pdfIn PDF document text
    • https://ietc-oman.saktoon.com/userfiles/files/rilija.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_off0000debf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBF 10756 bytes
SHA-256: 0ec945ec5e1d8683ba9abdf6d724c2a709fdcd1bd108e1532a4f4a9a47354a91
font_01_sfnt_off0000f764.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF764 19144 bytes
SHA-256: 6c93d201d6d2a37f5fb6115d1ca8791383e7e09cf43771bf4952a621d23dbf40
font_02_sfnt_off000127eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1