Malicious PDF — malware analysis report

Static analysis result for SHA-256 3878cc9fd0f2f0e7…

MALICIOUS

PDF

72.4 KB Created: 2021-09-23 00:55:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 98a4098e20691add18a905b52223f455 SHA-1: b54a2d2831254d20a2a9a3035f2db64152c684bb SHA-256: 3878cc9fd0f2f0e7414b81bfc495a537dee91ddbfc185b903f5930f16f6fdfff
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Several heuristics identified the document as a link farm pointing to potentially compromised WordPress upload directories. The embedded URLs suggest a lure to download further malicious content or engage in phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16135037c63626---92704970002.pdf In PDF document text
    • http://thermcom.cz/userfiles/file/84361099766.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/jubofuxav.pdfIn PDF document text
    • http://cowmoo.org/ckfinder/userfiles/files/zevezanamisufonadazizani.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/pajuzojuzelozazivuzuzeman.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/buvodegomofuwumegira.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/89487422398.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16142ffa2c5357---jazokuwenidisawelelikak.pdfIn PDF document text
    • https://phunhai.net/upload/files/90832782419.pdfIn PDF document text
    • http://muacuoi.vn/Pictures/files/75816886526.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210918184136.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/lazedo.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/16718350569.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/fozudisutusi.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/semipu.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/dotosa.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aab909ede0---56907552557.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/93560015266.pdfIn PDF document text
    • http://liily.jp/upload/file/20210908075259.pdfIn PDF document text
    • http://ebbers-schilderwerken.nl/uploads/files/petejinorutezop.pdfIn PDF document text
    • https://arendic.cl/files/jezikexixima.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/15086411453.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/lejodasanenifapaxazi.pdfIn PDF document text
    • http://textstricker.de/benutzerdateien/kuvewifovotubuwixoxin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=boxing+live+unblockedPDF 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_off0000b81c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB81C 17004 bytes
SHA-256: cff71ca9b79a0d3acd2947d75d4490191a890709665311894bc1362a03e80015
font_01_sfnt_off0000e3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC11 10572 bytes
SHA-256: 7470eeaf54a9641c21ab0c71c647d0fa56f28ec26d9add129bec9eb00aa0d103