Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a166177c187da19…

MALICIOUS

PDF

86.8 KB Created: 2021-09-16 14:45:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 62777873d2fb8f7438b7b0e5272a3a91 SHA-1: 23ff51325ab75364fef0c3994ddc709aff9352c8 SHA-256: 7a166177c187da19c68151c083306bf242fd4434a689df1434b9a8c2a629bb75
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple external URIs and link farm heuristics confirms the primary function of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://chcial.ru/uplcv?utm_term=master+2021+isaimini
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/tatofox.pdf
    • http://instalace-charvat.cz/userfiles/file/remujajaxegufok.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b648e306a---vojoninurinizuzi.pdf
    • http://52fotki.ru/ckfinder/userfiles/files/gutowisajelasuki.pdf
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/e6a3d5541a4cc3cae9159a5210cfa967/xorogujabegosatas.pdf
    • http://partnercable.com/files/96141370275.pdf
    • http://ghibms.com/userfiles/files/zenilumite.pdf
    • https://lasanisports.com/files/wugikenibunomum.pdf
    • http://animationcoach.com/userfiles/file/43101485734.pdf
    • http://jyjjapan.jp/files/ckeditor/files/dojizud.pdf
    • http://areawifi.com/DESARROLLO/userfiles/files/35912484526.pdf
    • http://veterinariacasettamattei.it/userfiles/files/59437734605.pdf
    • http://cerescommoditiesltd.com/Images_upload/files/ninibamotideradit.pdf
    • http://cantinachitarra.it/userfiles/file/46671097907.pdf
    • http://www.anjhimayath.com/upload/file/donefagifosukiviton.pdf
    • https://pmrmhss.com/userfiles/file/30018260773.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/161311fd2d040d---kulimumofix.pdf
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/ligeduxoweladivigataf.pdf
    • http://nwhouse.ru/uploads/file/29097738582.pdf
    • http://studiofagiani.eu/userfiles/files/47004081746.pdf
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/mosizenezupoligamekino.pdf
    • http://cluster006.ovh.net/~greeters/namur/ckfinder/userfiles/files/mafibife.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_off0000f079.bin
2ff3cea9718e4d1b55033285d49fe7f974248922beff8f8382830e1cda1013e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF079 10392 bytes
font_01_sfnt_off00010819.bin
847e545903e8288dd13bb71226770f4200b19e41a98147f07935370223de86f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10819 17736 bytes
font_02_sfnt_off00013643.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13643 16792 bytes