Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4acec354927ea75…

MALICIOUS

PDF

87.1 KB Created: 2021-08-10 01:06:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5e3be58faec11f389e4cb26a2e65a24b SHA-1: 6b6016925c11df1af5aed430086f0988fd4af387 SHA-256: d4acec354927ea7521e09f7f54c26f605f91d990e675440f49f2ee272ac2881f
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to external PDF files, many hosted on domains flagged as potentially compromised or disposable. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or distribute further malicious payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • 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://xlspandoek.nl/userfiles/file/momow.pdf In PDF document text
    • http://border-inn.com/CKEdit/upload/files/rimulizineridezuxamekugut.pdfIn PDF document text
    • http://skrn.cz/pic/file/vagofavasugumabozoge.pdfIn PDF document text
    • https://ahha.az/userfiles/file/fewawuxenavokasuzez.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202105/file/1621855636.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/82399796463.pdfIn PDF document text
    • https://eitmedu.in/ckfinder/userfiles/files/gozuvejifipumutujulizozo.pdfIn PDF document text
    • https://trexanh.net/upload/files/nazejegexevafitixipevuf.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16072769f75063---12827059241.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/65980072613.pdfIn PDF document text
    • https://badoza.net/userfiles/file/97859950460.pdfIn PDF document text
    • http://cgpreceptor.com/ckfinder/userfiles/files/60289414940.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/61865964382.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/pesuzefudevunupufos.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/84973287921.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/0a4ef28cc2d8b94f64c7b0ed2f739f0d/jesedasunivulop.pdfIn PDF document text
    • http://acevina.com/webroot/img/files/90219050704.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f874f4c597---76883228164.pdfIn PDF document text
    • https://nodka.eu/ckeditor/ckfinder/userfiles/files/17072064740.pdfIn PDF document text
    • https://nazrabilisim.com/calisma2/files/uploads/kuxurojibileninoduperofu.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/3e01b23c789d01698a330a72be0dbccc/77127773851.pdfIn PDF document text
    • http://suchanekstomatolog.pl/files/file/dakakotevibopogo.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/zorezagi.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094907cd99ac---sineze.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/1964cf9011be9b005d87f8b11b809baf/65356559538.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+renew+the+prc+licensePDF 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_off0000f1a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000109b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B8 17032 bytes
SHA-256: 0994498c8aeb49f0f2841cf157ed71c19483866fb45f0b537c255be07303ce13
font_02_sfnt_off0001362b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1362B 10384 bytes
SHA-256: 2929f6e1d0bf79bd06b17e40c428a13028b7755ae6cd4527dced68ba1ff7f605