Malicious PDF — malware analysis report

Static analysis result for SHA-256 16f85d38ac6400cf…

MALICIOUS

PDF

78.0 KB Created: 2021-09-18 13:46:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7e04047c48c957c7f0973589d028fbca SHA-1: 5fa2505ab8f3a2a796b1983735f610254e3db5b6 SHA-256: 16f85d38ac6400cf97fb77e17d98a1c13938be3a609e38125f4e0b179b547dd0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs point towards a common pattern of luring users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://krisoc.ru/uplcv?utm_term=textual+criticism+of+the+hebrew+bible+pdf PDF link annotation
    • http://veterinariogiardinelli.it/userfiles/files/fojosafudedopubunav.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/lusakufiweripofaxot.pdfIn PDF document text
    • https://thebillionbottom.com/business_school/uploads/file/47500577919.pdfIn PDF document text
    • https://locoffice.ru/userfiles/file/nimijuliwudovajog.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/files/ruwapimivurawajegur.pdfIn PDF document text
    • http://rakkhunnursinghome.com/user_img/files/jatubomefoxedolar.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/82785067320.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210912142652.pdfIn PDF document text
    • https://projectmine.hu/ckfinder/userfiles/files/guvitun.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/161434d139293f---7917746144.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/movisiveworavono.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161384212343af---74625240366.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/16138c7a9b00e6---xavobutejabukosuzomawap.pdfIn PDF document text
    • https://www.andreivieru.com/ckfinder/userfiles/files/98841416783.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/ludut.pdfIn PDF document text
    • http://studiocastigli.eu/userfiles/files/fuvixixe.pdfIn PDF document text
    • http://prefinancovaniehypoteky.sk/res/file/xiwotal.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/kizonunixezepibatedoluw.pdfIn PDF document text
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/legezoko.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/girazadefir.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/ligowadodoporaposorekemax.pdfIn PDF document text
    • http://blueyee.com/upload/file/100600081263.pdfIn PDF document text
    • http://xsteelstock.com/d/files/mezuvokejijudozazefe.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_off0000c9d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D8 11172 bytes
SHA-256: dc837060059d5e54f83f2c5334d5aac89d238176a1819953475389f1e43fddd0
font_01_sfnt_off0000e3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fbe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE6 17856 bytes
SHA-256: 4e60fb0b8a4d00e952997c9c8fdffb0c73f7dcde015d35f03ffcecc7d18b8d11