Malicious PDF — malware analysis report

Static analysis result for SHA-256 8890cb1fc5d47176…

MALICIOUS

PDF

112.2 KB Created: 2021-05-16 04:29:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 84548003de320f85168c490b84ebd5d2 SHA-1: de013c35982b0f6b4f536c7cb2491b15d2ae16f6 SHA-256: 8890cb1fc5d47176ce672bc263e1bc7c6269a9228aa9e7daa5c383d3abf532ec
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many of which are on disposable hosting, indicating a link farm designed to obscure the true destination. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this malicious intent. The ClamAV detection and ML classifier further confirm its malicious nature, likely as a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://golowaki.ru/strik?utm_term=cisco+7941+sip+firmware+download PDF link annotation
    • http://xelamoxadavas.mywebcommunity.org/thomas_calculus_instructors_solutions_manual.pdfIn PDF document text
    • http://tedisesux.22web.org/oneplus_6_review_android_police.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/bdd76576-b1af-4d7f-8a46-6686fae200ec/is_nico_in_love_with_percy.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ac460d82-051b-4480-9793-2b2f062dabfc/8797133502.pdfIn PDF document text
    • http://zutibebasonuf.epizy.com/zinoduduligorilasi.pdfIn PDF document text
    • http://nixomirorubu.myartsonline.com/fozivedazine.pdfIn PDF document text
    • https://aa514bbb-a96e-4bc9-8ff3-0ca2edd1104f.filesusr.com/ugd/3fc21f_a02adbed4d194a9fa2415fbeb81a653f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4bbc44d2-defb-45ec-bcf0-b9810dd828ab/cual_es_la_estructura_del_texto_instructivo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93a41be4-2cb0-40ce-9b8a-b5556707d579/epson_v7000_uv_flatbed_printer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05a88e8c-d63e-4a2f-8a57-c392e4fcd433/what_are_rhetorical_modes_in_literature.pdfIn PDF document text
    • http://virawumeritaxo.rf.gd/basavijidodim.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b06f8305-96ef-4ad3-b914-6f6fdc498adb/adobe_premiere_pro_2.0_serial.pdfIn PDF document text
    • https://969948a0-d7f7-4827-958e-a3856fee42d4.filesusr.com/ugd/9d40bc_9090bbd87e3d4d4e8094b84200e83d63.pdf?index=trueIn PDF document text
    • https://c4cd0dbc-23d7-4f11-b65f-2561cec8abe5.filesusr.com/ugd/516793_3b70f0d300fb4bf1b3a26b54ab1c0348.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/efe35e19-8f0b-4105-89b4-542d63fc51c2/wugabagaredufera.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15ea9cd5-1ee5-4775-942a-659db30a1e0b/did_you_hear_about_the_antelope_who_was_getting_dressed_worksheet_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d7cac2cb-3fd2-4f6e-a29a-14b3ef426875/25572112368.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/92667fb6-f059-483c-90bd-fbea13232d3e/45209948941.pdfIn PDF document text
    • https://a3c35cc3-4a3f-4d41-ab51-8b3e4b114d30.filesusr.com/ugd/2b25b5_d3c59a3494a04e669aaa5f04173f756a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/bfde1d0b-2a18-4d7c-8174-2c820373fcc5/kapunedakufetud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/908c00ae-43f0-4597-bce7-7dc85d750ccd/9768070786.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000168fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x168FD 5500 bytes
SHA-256: e9080f420692108c8b339d4bcf750977b4f1621a53bd86fe649ead153e3d31c9
font_01_sfnt_off00017bb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17BB2 11644 bytes
SHA-256: b0fcd0811613b350bf4d9b615f1f30102ec8dfef22242443dde4107b1024fd72
font_02_sfnt_off0001a387.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A387 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e