Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5a6332a3c35da4…

MALICIOUS

PDF

84.6 KB Created: 2021-07-01 12:41:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65ee0a39211c336463054dc93cbca6e6 SHA-1: b437f27212181446be9454d61c37f222c4fe9b1a SHA-256: 4b5a6332a3c35da40c7815f6edc08f308fa24428eac8be24811117d2692e0039
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external URIs and links to compromised CMS upload storage, suggesting it functions as a link farm to distribute malicious content or phish users. The PDF structure and embedded content, though heavily obfuscated, are consistent with malware delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://irlanc.ru/uplcv?utm_term=dungeons+and+tombs
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607750a3948bd---79171404054.pdf
    • http://alptw.com/images/files/dibusamakavonanoj.pdf
    • http://aire-limpio.com/img/editor/file/vowevulutawajej.pdf
    • http://softwarefactory.nl/images/file/tesonejojo.pdf
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/aaee360f5e3b3f02a4086fa7fe2efc25/66597722715.pdf
    • http://pc75.net/upfiles/file/1622807443.pdf
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/537d5a44d2e1240bc0812848bbb7d39d/13778052175.pdf
    • https://partnyor.az/userfiles/file/refujenutoxuza.pdf
    • http://aelma.com/sites/default/userfiles/file/jifuzujunovepewu.pdf
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f22a2030ae---didezetulamomiwum.pdf
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/7532dc06653ce68788d6ab55a6b764cc/vopak.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a094a173f03---18272391752.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-5-8/20210508143516360529.pdf
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/809675526231d8b2c994b2445f7c0233/mufukalibegaxobikivinel.pdf
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdb4fb75e4---fisomitufabox.pdf
    • http://www.celso.org/download/vakimesuwezuzabi.pdf
    • http://altaprecision.com/userfiles/file/morifazuvub.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9e423c5b83---lajiwakefego.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/0531973932bdc0e9ca0bd6655f8f0531/beruda.pdf
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/93481725174.pdf
    • http://canadanur.com/resimler/files/65130782944.pdf
    • https://southwestlooms.com/admin/userfiles/files/xefufigiporaroguxuxos.pdf
    • http://elsekmont.eu/userfiles/file/detufororanujulog.pdf
    • 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_off0000e707.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE707 16792 bytes
font_01_sfnt_off0000ff1e.bin
c8443ead1b062ef074a0a573c3070bbfce456e2029aaac0ebc74b4fd786cc202
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1E 10596 bytes
font_02_sfnt_off00011725.bin
461163eaa6742483be0126b0d65b3ca694a2403ceea4d06ece3b0dbae77a6ec6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11725 17332 bytes