Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cd3b0a26f332e9e…

MALICIOUS

PDF

86.3 KB Created: 2021-06-25 12:49:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ad84e52ac208c5f8974fc7dfa6209134 SHA-1: cea27f383194a6de53660646e9a8821f770537a8 SHA-256: 8cd3b0a26f332e9e9776615d0fa6d81efe6b6a24202639a565a8c7a0bc179cf1
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs pointing to compromised WordPress sites, many of which appear to be part of a link farm. The ML classifier strongly indicates maliciousness. While no scripts were extracted, the structure and URL patterns suggest the document is designed to lure users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://infrive.ru/uplcv?utm_term=how+to+do+a+mass+unfollow+on+instagram PDF link annotation
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf49585af75---57502699908.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2986d286cc---59263880198.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160820d954d891---79625545931.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/a50a62575144466a8b6f783db761f079/50213727342.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/d8eb000febdf8fa68345f0875b505465/88171221872.pdfIn PDF document text
    • https://birudongker.com/contents//files/83321982665.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/2a21559861ece35e2284ab867331e060/rogufowivedujowelonog.pdfIn PDF document text
    • http://cphs1970.net/clients/877309/File/44029024217.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/4464d16c856230e779b36aabbb906710/9994500812.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/4f986d1fc49efc23d519a768212cbd78/14995219570.pdfIn PDF document text
    • http://atrsara.ir/resource/files/20651396171.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/xugasazuxijasamokeferabe.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210625000252_s8gzxo.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/31cef91c221be1a8dd93fd5167d344d2/86164269866.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160acdab51b773---gilebedepuri.pdfIn PDF document text
    • http://perfekttorun.pl/pliki/98031814150.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_off0000ec57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001046e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046E 10740 bytes
SHA-256: 830ea27726acc38b8121903eb8c1c8ec9b10079691b831ac615373e6d1cac2fc
font_02_sfnt_off00011cd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CD8 18256 bytes
SHA-256: 491b32c1f6455164c2be72268b53bee032d28c918f32e1cfca88ebb0591b01c5