Malicious PDF — malware analysis report

Static analysis result for SHA-256 875b3aa7f3381e3e…

MALICIOUS

PDF

71.2 KB Created: 2021-10-04 07:13:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 07bf4fecde171f8b1d013fa3435f2937 SHA-1: bc8c92871e06b69d350fb5abd1b3707768b4da6c SHA-256: 875b3aa7f3381e3e235103de09dc99f3ad95728c2b1ef2b8f8fc41bc85411f1c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifies the sample's structure as a link farm on disposable hosting, reinforcing the phishing or scam-related attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=what+determines+the+degree+of+polarity+in+a+bond PDF link annotation
    • http://rzn-house.ru/upload/file/42095680047.pdfIn PDF document text
    • https://sweetburden.com/upload/users/files/6051136270.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/57895582701.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/75350446000.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/midudumopelunarugowinamu.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/97233706234.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202110020803473540.pdfIn PDF document text
    • http://yung-shun.com/userfiles/file/42908917347.pdfIn PDF document text
    • http://erpsamik.com/ckfinder/userfiles/files/famevaruwofuzogefanabiti.pdfIn PDF document text
    • http://perfekt-dom.pl/designhome/admin/userfiles/file/vexujelatujorurukuwojesu.pdfIn PDF document text
    • http://studiogeologicotrilobite.com/userfiles/files/kuguwarewogowimanir.pdfIn PDF document text
    • http://hykylalumni.org/userfiles/jadokikavijazukitomasibo.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/dobegiverapukapavip.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/moxatomu.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/gonewedutukusifebubo.pdfIn PDF document text
    • http://goksirlambinowice.pl/img/upload/files/73841584826.pdfIn PDF document text
    • https://dfkcnc.shopper-store.net/file/files/41697694779.pdfIn PDF document text
    • http://embody.box8websites.com/ckfinder/userfiles/files/36544842954.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/migosadijekuza.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615599d84bbf4---5933734591.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/9558074081.pdfIn PDF document text
    • https://vienhung.com/webroot/img/files/27315425921.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/90980993948.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_off0000b2cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2CF 11192 bytes
SHA-256: b659b67313ab82d222d2f2a3491339de2226212a8c66c6b9093f91986997a900
font_01_sfnt_off0000cc62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC62 16860 bytes
SHA-256: 771c65993122684e279e024da4282fe4a616335a348c03a1a721686f002086ae
font_02_sfnt_off0000f6de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1