Malicious PDF — malware analysis report

Static analysis result for SHA-256 903369dcecb658f2…

MALICIOUS

PDF

68.7 KB Created: 2021-10-15 19:22:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b3a28f900a66ebbc47f1276dbf251fb5 SHA-1: df29990904b695ff8b62da10ada59a6a617a8a52 SHA-256: 903369dcecb658f217f86c112e8d73400b2985e6d22cfa08e0f495c01ef94a0f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which appear to be hosted on compromised CMS platforms or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure itself does not contain readable content, indicating it's likely a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://eptesteplelek.com/uploads/file/rolijozefikebujuz.pdf In PDF document text
    • http://thepokeluau.com/uploads/files/rijutupufuke.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3fd302309---xebuduzajedefa.pdfIn PDF document text
    • http://xn--80aap0abfiql8h.xn--p1ai/admin/ckfinder/userfiles/files/58531372543.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/62156499907.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109301808226963.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/detuwod.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/60557563393.pdfIn PDF document text
    • http://vladekoservis.ru/files/taxonetinu.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/29394136376.pdfIn PDF document text
    • http://gccde.com/downloads/blog/geust/files/guvoriv.pdfIn PDF document text
    • http://karinameal.com/imgdish/files/dusisotunasixisorijuja.pdfIn PDF document text
    • https://marbeyoyun.com/calisma2/files/uploads/31717449916.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/40971359852.pdfIn PDF document text
    • http://gymostrov.eu/gymostrov/userfiles/file/rabokonesefim.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16164cf7f377e7---43511378249.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/xoratofusoxogafaj.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1615bbd83116a0---zofel.pdfIn PDF document text
    • http://inimtrento.it/userfiles/files/selob.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161660985b7cac---90868992588.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/jowizububadalanule.pdfIn PDF document text
    • https://hargagila.com/uploads/image/files/81306425116.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/UsNeCLCzgYg/uplcv?utm_term=griffin+memorial+hospitalPDF 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_off0000adb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADB7 15660 bytes
SHA-256: 695ebe1be2b5cbb938eaf709e9741ecea41142cd50777f827aefeee58162b8c1
font_01_sfnt_off0000d54f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD54F 10664 bytes
SHA-256: a6324f1d0b1952f1a5145b90d04268867863861192746d7efd8141f659eb6ba3
font_02_sfnt_off0000ed8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1