Malicious PDF — malware analysis report

Static analysis result for SHA-256 efa91bf0a9357124…

MALICIOUS

PDF

69.8 KB Created: 2021-09-14 00:25:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6b1ceb94765a874516d333773c00afc2 SHA-1: 6bd927655a4ddb5c95710d2f8e8bfe31607b05c5 SHA-256: efa91bf0a935712417f283c67b08d27ec74bfad90e4456db0ff849681ef9b4bc
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. The primary goal appears to be directing users to external, malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://oralrem.kz/ckfinder/userfiles/files/dafejonimimelepizovaxaniz.pdf In PDF document text
    • https://loctra.net/userfiles/file/bodijalosufe.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/37294334c71732c191b7bdd139f4bf01/33939222537.pdfIn PDF document text
    • https://gamaconsultores.cl/upload/file/32166620143.pdfIn PDF document text
    • http://marine-inox.com/i/File/7311740307.pdfIn PDF document text
    • http://humansharehouse.com/userData/board/file/jojudijalij.pdfIn PDF document text
    • http://tuhocxuatnhapkhau.com/uploads/ckfinder/files/24733633534.pdfIn PDF document text
    • http://champaigncursillo.com/userfiles/file/vapabevizisobemegu.pdfIn PDF document text
    • http://buren-kompanie.de/userfiles/files/34183002081.pdfIn PDF document text
    • http://sola-brothers.com/userfiles/file/wegasodokadotawogoxuwul.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbfb51f524---771553590.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/83906692958.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c90c2c05e---dapitavaniguxiro.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/96496727458.pdfIn PDF document text
    • http://azstorestudio.com/uploads/files/tixaw.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbcf5988d4---45866831479.pdfIn PDF document text
    • https://aksusu.com/upload/files/25396746579.pdfIn PDF document text
    • http://nova-auto.com/upload/zaruwarap.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/67005894771.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/4dfdbaed8beafd783283d672b4a0f5aa/zafidapuvubar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=madness+combat+free+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_off0000b102.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB102 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c919.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC919 10768 bytes
SHA-256: 2cd802c3c0aa1c6387b3428959e4aad46e8ac29e1c3310074414beec1fd8c66d
font_02_sfnt_off0000e1ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1CA 15720 bytes
SHA-256: b5e54cde766a83f74fdd00323e29fa3f6a2537e31cda1ac527fc05767e843e34