Malicious PDF — malware analysis report

Static analysis result for SHA-256 428b0639d7207641…

MALICIOUS

PDF

89.4 KB Created: 2021-07-07 22:01:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: dabdcdae48c9f88991b6cd966293d163 SHA-1: cd42b6abda98ffd978a7a000d004e8e9e854b0b7 SHA-256: 428b0639d7207641760370fdc30dbc1004cd3531f76f9eaf955b7bf27c314154
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links, many pointing to compromised WordPress upload directories, suggesting it's designed to lead users to malicious content or further compromise. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the structure itself is the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607bab608eb73---45663347017.pdf In PDF document text
    • http://brilliantsolarpaneling.com/userfiles/file/3058374316.pdfIn PDF document text
    • http://thegioioto.store/upload/files/nikev.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/vl5rbdd561puhpccngbprevif5/kawobipovodega.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/b8606103dd0177fa36208ba4a1b5a077/fivapiwubadatexobosa.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/23598309064.pdfIn PDF document text
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/vevosenoribelagokovub.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/g9pusfv47364qndi33qrfoietn/62092314642.pdfIn PDF document text
    • http://wrhs1967.org/clients/6/61/617565fc8afb9cc6d18abf932d248b7a/File/19940910537.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b3184e7f660---54614566638.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098c8424d25a---51804454451.pdfIn PDF document text
    • https://q-web.ro/wp-content/plugins/super-forms/uploads/php/files/9pudb5tdtpc51hc4gkeohikqgr/tixidaj.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/0f43741b90013726e3ed5c8fdff2bd16/19335445361.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd899c6d50b---40718944207.pdfIn PDF document text
    • https://vpntraffic.com/upload/files/31263191938.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1606f17883ace0---minovojidotof.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160945e699619d---88069918489.pdfIn PDF document text
    • http://dharmapremipariwar.org/userfiles/file/14367090453.pdfIn PDF document text
    • http://slhs1958.com/clients/18590/File/xeruwemesikifon.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1e54b38134---38055535516.pdfIn PDF document text
    • http://cfh2.com/clients/d/d2/d2a7b52150a7a947468b52e9b7560e3c/File/7653351548.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094785ab82a4---87517452144.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075bc1c4e0b3---wadup.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bbcaa11c1e6---tudunipakafifotad.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/e1bd0497db11891ace9c08ee7571cae2/roxuxodejed.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/16f80a4097a733b4926fb88e1f4b12df/63434717128.pdfIn PDF document text
    • http://smclassof57.org/clients/34860/File/lixozakugosijuwugapab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=frightful%27s+daughter+meets+the+baron+weaselPDF 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_off0000f7a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A0 17084 bytes
SHA-256: b23f9cdd8f4d01cfb5e8770ec8b7b4817fa303ce397031ce139d050be44f1541
font_01_sfnt_off0001246b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1246B 11136 bytes
SHA-256: e743d282e7176263db87170e7d0be8f5dfdd39aeb7162a2305f8877adedf2d5e
font_02_sfnt_off00013e15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1