Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4c9d1e205865f37…

MALICIOUS

PDF

68.0 KB Created: 2021-10-02 04:44:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 838d8543f69567d92912bf89dca7de3d SHA-1: 71cc432655adbb0be92c047e7e818dcfe3d32841 SHA-256: b4c9d1e205865f370bf298d287d9fbbb14afe402b771dc1fd8c27f97a8089866
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads or disposable domains. The embedded URLs, such as 'https://catamma.ru/uplcv?utm_term=cd+key+office+365+free', suggest a lure for potentially malicious content or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://catamma.ru/uplcv?utm_term=cd+key+office+365+free PDF link annotation
    • http://pinzimoniofiumicino.eu/userfiles/files/18759298221.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/14761891682.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/laranaxagivuzerifewamam.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613060e37aa3e---17336885080.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/davigaxopulegajebijizobo.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16153016195ba4---fazowipifaj.pdfIn PDF document text
    • https://il-gusto.com/images/file/bidejekudobetutap.pdfIn PDF document text
    • http://chothuethietbi.info/img/files/21258468630.pdfIn PDF document text
    • https://makenie.com/upload/files/tazufali.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210908004404.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/31539302530.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/a445190f8e180f3174941a13fd0c4cc0/12909077751.pdfIn PDF document text
    • http://compufoxmail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/tofajaxirolakaxare.pdfIn PDF document text
    • https://huaienclinic.com/uploadpic/files/xobubowoz.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/11277gpih9139fog86f22kn9km/tivovozakanesur.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///debozawo.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/22218793043.pdfIn PDF document text
    • http://luijkzonwering.nl/image/file/52470431418.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/metirumuwububarujovogiv.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/lawometitiniratibokug.pdfIn PDF document text
    • https://girilawfirm.com/content_files/files/somigavevabusizipaju.pdfIn PDF document text
    • 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_off0000abe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c3f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3F8 10600 bytes
SHA-256: 5b00f67be8129add22f638f7a83d39a1811041d68b2ca46d1b956a4664eb9610
font_02_sfnt_off0000dc5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5E 15288 bytes
SHA-256: 636ebb49ca5fcabb47b6b20b1c8f19399f86e0ca9f293967f714f812ff307f1d