Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d91fea3aaf3a35c…

MALICIOUS

PDF

72.7 KB Created: 2021-09-16 20:42:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b1b4f59d0333b5849384a46828591652 SHA-1: 9d40c853dd01ca00576e6cb7e313307ff604b507 SHA-256: 7d91fea3aaf3a35c1060a794cabbf88723597fc075a5b6feffad12e127c9244e
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM firings strongly suggests the document's primary purpose is to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=hof+free+spins+house+of+fun PDF link annotation
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/6664027b0018eeece16c151a7a6c7f91/nejesizozasexedizag.pdfIn PDF document text
    • https://tumsad.org/img/editor/image/file/tudixanamadavo.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/4b522cf3a7cc1b9f42caae8108655491/zuborilena.pdfIn PDF document text
    • http://yuc-fac.com/uploadfiles/20210915150416.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/babuvulekapu.pdfIn PDF document text
    • http://skisun.it/userfiles/files/loludafawavaberubuxikonas.pdfIn PDF document text
    • http://hakanhurdacilik.com/userfiles/file/kadutaporum.pdfIn PDF document text
    • http://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/dovofuvawovukanetoxewiba.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/4ri0uspdhkiimohp1gbgjkkn43/1268184463.pdfIn PDF document text
    • https://feldmann.pl/userfiles/file/fodas.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/17719875023.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/60952154743.pdfIn PDF document text
    • http://karthikeyanjayaram.com/userfiles/file/fokibuvewogo.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161402191100de---denugufu.pdfIn PDF document text
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gizuwikojirukol.pdfIn PDF document text
    • https://nabil-doukali.com/userfiles/file/xexujupelojivu.pdfIn PDF document text
    • https://lifeteacher.tw/uploads/files/202109032155358245.pdfIn PDF document text
    • http://theonejsc.com/userfiles/file/86016537997.pdfIn PDF document text
    • http://ktcyy.com/ckfinder/userfiles/files/losegesezozubijajebabal.pdfIn PDF document text
    • http://newtrichur.com/userfiles/file/tiwefa.pdfIn PDF document text
    • https://maintogelonline2.com/contents/files/26497768257.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/66990091335.pdfIn PDF document text
    • https://tramhuonghanoi.vn/upload/files/lidazofewel.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0c494f63d---96755502375.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_off0000bae6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAE6 10240 bytes
SHA-256: 1ee68bbfb71cff590edf01c72576b6d782b437d6c2dcf5790630345ac3d9d437
font_01_sfnt_off0000d1c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1C1 16720 bytes
SHA-256: 6895b486c342566f1eb76577f562dac947746877b9b0886e137c9621974d6a0b
font_02_sfnt_off0000fd72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1