Malicious PDF — malware analysis report

Static analysis result for SHA-256 815d8aa9bf67c117…

MALICIOUS

PDF

112.2 KB Created: 2021-06-09 07:14:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: aed95993945aeccb96195ed3f376bc2a SHA-1: db9647eedea0f61991b354af73c170e42edbf301 SHA-256: 815d8aa9bf67c1174a7f84a0d61b530f850d051c667fda244b95736998416a50
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external links and the nature of the heuristics point towards a spearphishing attachment as the initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=immortal+beloved+full+movie+online PDF link annotation
    • http://alliance-ltd.com/userfiles/97855959124.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/c0e366c667ada75155b56638ff8c6ff4/55963133795.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098858e7b04b---manatotizodurumig.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8e1347921---57272328443.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609b978863a2f---83042956739.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/01qsmf4j4eetrnlugtlkjbt1j0/posibexenazala.pdfIn PDF document text
    • https://amblamy.ee/upload/file/88765618592.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/c44c7aff295c40b5c8f3f1ad6d4d5eba/96009627456.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe6647d9a7---zabiruxufituluronip.pdfIn PDF document text
    • https://schmitz.cz/res/file/vilakinesigikesoxupiferov.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/583d489fe4a94ceba7cf5cfbbe030514/94940327506.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/tibopilenoxopasexaratazu.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/qmj939jpb8quj31kt8knkiae7f/tefalijajudelukego.pdfIn PDF document text
    • http://dentherapia.hu/files/file/xujikikolutitenonim.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/88018eb0336984f74c69e23778b34f90/13407626983.pdfIn PDF document text
    • https://coluer.ir/documents/file/gedozig.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/8e29452f1a17eebf35a5f98981052d70/41229402335.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001791e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1791E 5012 bytes
SHA-256: ba92db0611992c1b8005a152da3e1a868db59a4d76b68c760494dbfb79e678fc
font_01_sfnt_off00018a15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A15 11600 bytes
SHA-256: 370d85ec54453bbef9175647e4ec568f211d7d5051d5c8f23c5be0133da91380