Malicious PDF — malware analysis report

Static analysis result for SHA-256 871f963c23b0022d…

MALICIOUS

PDF

87.3 KB Created: 2021-07-02 02:36:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b6673dd798fd7aa288bb012149f06192 SHA-1: ddd0d4553dcd7a21fd843bd4c737e35b98960715 SHA-256: 871f963c23b0022dbd289b699022cabfba35dce5a4cfcb897859ae69328698f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to obscure the true destination or track user interactions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://asbu.net/uploads/FCK_files/file/67087771498.pdf In PDF document text
    • http://botosani.ro/img/uploads/file/65652314708.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/de082411f82ad9b5033462385f5672db/98132218060.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/19740805685.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/d9741bdc41baf04d01ad4f7d0a30ec61/jokigobuzejak.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/advnsj9v3utqmcb9njvk6iilti/dovek.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/nhd28jrqpp9l8og6l0r3bi3pr0/nekutafisaniwitigubufarow.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/3006db754b87384eb36d8b6ac722b437/zarixuxevododoz.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/1196342297.pdfIn PDF document text
    • https://peterdegendt.be/file/vokuluwu.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/u78dvd8rndb8588p56kdf1o53f/16453816591.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b861539b44---wodenikotebiga.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943a61e2af7---mivemazilotilamuxekusik.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/3797616901.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1607f13e0b4c89---todapodifoba.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608af768be8f8---4662208497.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160ba17ba34792---29428756833.pdfIn PDF document text
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/533873ee6e17783f2ed9bff6c443b958/diranuk.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6fdfc62a4---71465527386.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-6-26/20210626022722658553.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7814094b9c---47008819813.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gokezetedak.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/53649243560.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/iibrthuivq47qvber2fho5nun0/91941637251.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=function+of+vacuolePDF 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_off0000f428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF428 17160 bytes
SHA-256: eef97e54868daa936a65495ddb2f1b2f50bf761edfab115b940ac94aa32ff931
font_01_sfnt_off000120f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F0 10204 bytes
SHA-256: 7198554ea51bcfc3c2fe8ab2917090059b2182c88c110d917ebc054d351f1b26
font_02_sfnt_off000137f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1