Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac0f7550f3b76653…

MALICIOUS

PDF

70.7 KB Created: 2021-09-29 06:43:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fa3f026359e997637df300dd7617bf50 SHA-1: ba0f715dedf86a2878c44380c2d44b976ff6552c SHA-256: ac0f7550f3b766535894ec6db931afbc5c1b0210333cdf87b15ac1486f8ad27e
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO manipulation. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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://architettogherardi.eu/userfiles/files/jiniterijikufebira.pdf In PDF document text
    • https://phucatgarment.com.vn/ckfinder/userfiles/files/29494840916.pdfIn PDF document text
    • http://giorgimpianti.com/userfiles/file/5176796395.pdfIn PDF document text
    • http://waypl.pl/upload/File/13722435377.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/16934519521.pdfIn PDF document text
    • https://inprovitvenezuela.com/ckfinder/userfiles/files/bupenemo.pdfIn PDF document text
    • http://fanghsin.com/uploads/files/202109012002283097.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109081613561017.pdfIn PDF document text
    • https://edubox.mn/uploads/users/0/files/9330846803.pdfIn PDF document text
    • http://auroraenergyproject.it/userfiles/files/suterafikutokasiwikifar.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/jekol.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/jirugitoforokijosubusizi.pdfIn PDF document text
    • https://kiofruits.com/admin/uploads/files/77624031434.pdfIn PDF document text
    • http://reyazahmad.bscsaoner.in/ckfinder/userfiles/files/bawerawu.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16143144a350f5---gagukulaturiduditajogumep.pdfIn PDF document text
    • http://xn--c1adbeke4asdefy.xn--p1ai/ckfinder/userfiles/files/5900724520.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109191020491888.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/50242072097.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/20210926/210926192616608538m6tsep15mkbd.pdfIn PDF document text
    • http://i-akparat.kz/ckfinder/userfiles/files/46903854714.pdfIn PDF document text
    • http://uceng.net/_UploadFile/Images/file/momatotosunaketajepeki.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/58c1045182afb7d2f91b493b53b9fe12/1838802003.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/6b7f266745f128a61276d2a9593118ec/38753609553.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=dragon+ball+super+in+english+watch+onlinePDF 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_off0000af49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c760.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC760 10980 bytes
SHA-256: b251e2ad017dcd24cb140ac3cc73441f94589f36a58b7a2c9d44e1b9e83013c9
font_02_sfnt_off0000e0a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A3 16820 bytes
SHA-256: d8485b583ca5029709090db76298fd95d6aa03cb03fa773e6c030a0668ab7b9b