Malicious PDF — malware analysis report

Static analysis result for SHA-256 1837ba8e05324888…

MALICIOUS

PDF

77.8 KB Created: 2021-09-01 15:38:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b0ee19c972d8797b8d3a1ad9c63b4d2 SHA-1: 01d3065deb61ef2255532f378031a4d8ff5bb6f9 SHA-256: 1837ba8e05324888caa8d085324a2c867078648ca657d4def05cec13fa67801d
164 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several pointing to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of a 'download button' lure further supports a malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://presstone.hu/userfiles/file/xasokijevopepu.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f1c7fc84b88---42844379384.pdf
    • https://perfecthospital.net/FCKeditor/file/ginibikuli.pdf
    • http://wjcopy.com/upload/files/vanizavu.pdf
    • https://airflow-skateboards.com/userfiles/files/latepedoxujinuti.pdf
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/5128250612.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/bodgelhghedl726tl9pj6mv6b8/xegufeta.pdf
    • http://nato-denkmal.de/uploads/file/2026043158.pdf
    • http://winhazel.com/indigo/ckfinder/userfiles/files/zubogiwafikelidik.pdf
    • https://alev.az/userfiles/file/17279558338.pdf
    • http://szyuangang.com/UserFiles/file///mesomagiselotofixokidizif.pdf
    • https://vozilasavozacem.rs//files/53472145280.pdf
    • https://milkyway-vn.com/upload/files/31341955615.pdf
    • http://merlegdoktor.hu/tmp/49553452198.pdf
    • http://wchs65.org/clients/b/bb/bb65574a37642f7fe3135935df861e67/File/gagatugafubarinefeba.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/m3ookcgj7iemb8l3hhs0h3hb73/38598794041.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1757d526da---makipejibosawagagez.pdf
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/72886515963.pdf
    • http://commune-bourre.com/userfiles/file/59947249388.pdf
    • http://dannguyetltd.com/upload/files/wowobaselozagomozorupa.pdf
    • http://runningrhinelanderrabbitry.com/clients/875187/File/46445095749.pdf
    • http://vo23.ru/upload/file/43818550998.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=4856+continuation+page
    • 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_off0000cb3b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB3B 16792 bytes
font_01_sfnt_off0000e34d.bin
f1e249d575f35c5faa3ee774d0d057180cfc030a47a50caf6c3f4faf152a76ce
pdf-font-stream PDF embedded font (sfnt) at offset 0xE34D 17008 bytes
font_02_sfnt_off00010f6b.bin
adc13f117b5b3943fa2c1b3919c222bbdeeda2b01e8ae09e28ed58758019ea74
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F6B 10828 bytes