Malicious PDF — malware analysis report

Static analysis result for SHA-256 16eec1d57e573558…

MALICIOUS

PDF

78.3 KB Created: 2021-07-01 15:34:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6f370da7a1670e6fe38cae033d40c110 SHA-1: 802f41b26760dad560fa2969dae080a00e817090 SHA-256: 16eec1d57e573558a38eb52e3908f56f3b905dd60207a5208bf312c06a3492e3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or redirection mechanism. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution lure, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://inwebjor.ru/uplcv?utm_term=but+if+you+wanna+cry+cry+on+my+shoulder
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/5863ab91582115237bbb1837c3d68b52/37086336318.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c106627e47---8481861598.pdf
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1d53857fb4---45819044471.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/17617214718.pdf
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/33137655089.pdf
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/1531bc7146a0abbfd03035468fc8ce08/91970118033.pdf
    • http://broadgatecapital.com/userfiles/file/rixirefo.pdf
    • https://studiovizia.com/webroot/img/content/files/24758652584.pdf
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/3447a663521bf2dfb1fab6f87fb4f2cd/natepuzejumazajex.pdf
    • http://tamker.hu/userfiles/file/nexazodojeta.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16077cc322457e---gatuzabapurirebakaked.pdf
    • http://op-gold.com/ck_image//files/62801310019.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c54fba816---74181647965.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/a86u96ev9p6ntk6pspom74e3vm/87393432327.pdf
    • http://stacjaregeneracja.pl/userfiles/file/46825271288.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16072b30ad83af---85568847522.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbe312d31d1---putulufunagebipeluxawej.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160834c6eeddb3---92367312243.pdf
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/68ef1a604e7dc5132f2e03cdc329bbf7/28432059670.pdf
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609611f8d9722---32841853655.pdf
    • http://evopizza.lt/ckfinder/userfiles/files/purezagaxon.pdf
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a56d78413---daxolijixe.pdf
    • http://xn--knstlerische-biografie-arbeit-lbd.ch/userfiles/files/bawuzibetukifexutalo.pdf
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/ce8cfa772a52547ca2d4b158c68a47c9/34374099529.pdf
    • 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_off0000cdce.bin
6cfb025f2caaff48c7aaa802a9426e37eb7f754972345d2f7c2ee85f81d26734
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCE 16868 bytes
font_01_sfnt_off0000f9d4.bin
824d18f5ba5110a0c9a7ef7c4040058531abb7d363664c8bed39262b023b02ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D4 11096 bytes
font_02_sfnt_off000113a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113A1 16792 bytes