Malicious PDF — malware analysis report

Static analysis result for SHA-256 a67707671cd20aa9…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 21:56:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fa4de8f1c4b1e34e3246bf53f3529cb5 SHA-1: 0e6f6b9482cbd455ddc5cfdd2810ccbee427c888 SHA-256: a67707671cd20aa959c0fd75dc5f1fc220675622faa5c23c2187c2b11dc83bcb
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. Heuristics indicate it functions as a link farm and a callback phishing lure, prompting users to call a phone number. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it is designed to lead users to malicious sites or engage them in social engineering tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://chcial.ru/uplcv?utm_term=android+beta+psp PDF link annotation
    • http://tecsun-moscow.ru/docs/file/nowif.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/14267972789.pdfIn PDF document text
    • http://dorinhawear.com/admin/fckeditor/editor/filemanager/connectors/php/fckeditor/editor/filemanager/connectors/php/userfiles/file/87215844560.pdfIn PDF document text
    • https://www.bussmann-tiefbau.de/ckfinder/userfiles/files/96329244711.pdfIn PDF document text
    • http://farmaciafasolis.eu/userfiles/files/66733612788.pdfIn PDF document text
    • https://jotekonybakterium.hu/userfiles/files/xugadinodotavajaja.pdfIn PDF document text
    • http://dhf-china.com/d/files/25383504012.pdfIn PDF document text
    • http://baohanhranghm.com/upload/img/files/durunusidomip.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/33822899751.pdfIn PDF document text
    • http://roocenter.ru/upload/file/12348553336.pdfIn PDF document text
    • https://tmtteks.com/files/wojewusawibemi.pdfIn PDF document text
    • http://protectakoteasia.com/ckfinder/userfiles/files/lugafadojopabovewafigakur.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/23633054345.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1613e61ea64f86---misutixu.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/semulowotimaxuji.pdfIn PDF document text
    • http://gmart-express.com/demo/uploadpic/file/finavegitanobamuvav.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ba82488d1---wujabawarimuguroguj.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/kivavetepufejeji.pdfIn PDF document text
    • http://daisytalavera.com/userfiles/files/moroderaganuxivujagedir.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/18325104184.pdfIn PDF document text
    • http://tctrack.vn/images/newtech/files/22072017745.pdfIn PDF document text
    • https://peusch.lu/userfiles/files/gekedetoseluwadaxana.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/77398773333.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210906192118.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/metijemukidubugu.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_off0000db1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF332 10460 bytes
SHA-256: 86478f630a89f0f8562ac2ce280f3e31e9f9f3f2c9883e4ff79a145c29ed9372
font_02_sfnt_off00010ad5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD5 17360 bytes
SHA-256: c6be3b4cc8859e3270f3a1617c439685a3e312215f862e85a333aa20f7514a19