Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9ef6be8639f4bb9…

MALICIOUS

PDF

75.5 KB Created: 2021-09-19 16:51:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: df3a103794576258d7a8168ca4ca0dbb SHA-1: 3f58703faf30ad75d017999412c007ab28f47f95 SHA-256: b9ef6be8639f4bb9c82bc7e805194392ccf58d5c463b4f75cd9e09cae91fe77f
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to various websites, including those hosted on compromised WordPress installations. The primary goal appears to be directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://stringquartet.biz/web/images/fck/file/zoravotigubarudutevaka.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423977c7395---biboma.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613539ddb0229---63492023636.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/38016992736.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/60944521374.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/dovijapumaw.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c1e5db25d---wobatawudotenopidobesor.pdfIn PDF document text
    • http://biblioteka-belzec.pl/upload/files/81683299971.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/jabedelamodobofutupuj.pdfIn PDF document text
    • http://playitdirect.ca/ckfinder/uploadfiles/files/9774801116.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210908153508.pdfIn PDF document text
    • http://droprint.my/home/ququ4923/public_html/userfiles/file/mabejulu.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/83187203272.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e591dae58f---ponov.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613147a445505---vilikibo.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/a8bd81c680956c52472eaa3a0d3e2f79/tiramewewof.pdfIn PDF document text
    • http://tythb.com/uploadfile/files/mizavebowatodugomijaxiga.pdfIn PDF document text
    • http://fazekaskozpont.hu/images/upload/file/jabebab.pdfIn PDF document text
    • http://cen7dias.es/userfiles/files/97176610458.pdfIn PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/40186258191.pdfIn PDF document text
    • http://fanta-life.com/userfiles/file/95337752858.pdfIn PDF document text
    • http://ilovehikari.com/uploads/files/91208936095.pdfIn PDF document text
    • https://jeevadhara.org/work/london/userfiles/file/36690843606.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=configurazione+internet+wind+huawei+u8815PDF 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_off0000c17d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC17D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD994 11092 bytes
SHA-256: 38a47cd51cceb2fedd909e20d952ed1bea95bcab9f4793cb665ffb9bae2bbf72
font_02_sfnt_off0000f36b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF36B 17452 bytes
SHA-256: bc17cd02fcfdc96645d3fcfe10d32a719980437f0fb7a0f00652cde4bf909784