Malicious PDF — malware analysis report

Static analysis result for SHA-256 171843f66cbc2fed…

MALICIOUS

PDF

83.7 KB Created: 2021-09-10 20:16:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4ffce8bc7c9c907bd842d36d47d03900 SHA-1: 1867ea7739c68d1892f648d1fe1e0aaa6467c8ed SHA-256: 171843f66cbc2fed4f4dfc9373e62bea9e7ba2a17a48bdb3b5f0316e045ca985
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure and embedded URIs point towards a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://immobilieninvestors.de/userfiles/file/33919081867.pdf In PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/tuvenitorafulivojaxizemi.pdfIn PDF document text
    • https://lorus.rs/files/lofitatefuzaxug.pdfIn PDF document text
    • http://helenhotel.vn/upload/files/89287016825.pdfIn PDF document text
    • http://blessingsngo.in/userfiles/files/80443691844.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b81a6cf6d5---gulaxedegokolajebitewer.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/lubalebediki.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/fifota.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/29767631996.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/kumesovop.pdfIn PDF document text
    • http://gucaoyun.com/uploads/file/040923453163.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/34044212890.pdfIn PDF document text
    • http://salocchi.it/userfiles/files/55588301804.pdfIn PDF document text
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/pejomujaroxaleravow.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613797f0a8163---pisugumogazerejigoz.pdfIn PDF document text
    • http://www.ks-klinika.ru/ckfinder/userfiles/files/80220702977.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec729bacf2---pizidovirifajuwik.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/naxibuxugamubafosagin.pdfIn PDF document text
    • http://theurbanbazzaar.com/userfiles/file/87094949649.pdfIn PDF document text
    • http://centronegozi.com/public/jasawatomukuviruzimivit.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/wisuvepeguwaxoxurofa.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/16555763708.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/roxag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=alight+motion+apkPDF 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://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_off0000e3ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3CA 17924 bytes
SHA-256: 193b2ea95ce8c8b5398d3b27ce97b8d8dcd2679f422cf3db070bbe0778b1548e
font_01_sfnt_off0001122f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1122F 10372 bytes
SHA-256: c98cbfecfa014c4b5e0a8b58565dac5c6fb09772d2f130976be0824459fb7e59
font_02_sfnt_off0001296b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1296B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1