Malicious PDF — malware analysis report

Static analysis result for SHA-256 a42535e675e4265e…

MALICIOUS

PDF

71.3 KB Created: 2021-09-25 07:25:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 932855fc1bfa2ad6fa5c514b4735938b SHA-1: 5542439d3aa1fd43d11013d36809d82c4aa62272 SHA-256: a42535e675e4265e203c7f8c2210438de2157dfe6717c3421cf9a903159c9c74
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and multiple external URIs, indicating it is designed to execute malicious code or redirect the user to a malicious site. The 'SE_CALLBACK_LURE' heuristic strongly suggests a callback phishing or tech-support scam, where the user is prompted to call a number. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chornakorn-packing.com/ckfinder/userfiles/files/67495259465.pdf In PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/vinafalowafe.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/japebaxelasoregekofuvowu.pdfIn PDF document text
    • http://hflchw.com/upload/file/39910980983.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16139ff2c7f27a---51128126452.pdfIn PDF document text
    • http://park-seversk.ru/other/js/ckfinder/userfiles/files/44620767148.pdfIn PDF document text
    • https://o-dance.com/upload/files/pesasopuba.pdfIn PDF document text
    • http://specialcats.nl/media/files/54446011487.pdfIn PDF document text
    • https://777mto.org/contents/files/vutiwirusi.pdfIn PDF document text
    • http://nandishoverseas.com/UserFiles/File/62054839507.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/13924815341.pdfIn PDF document text
    • http://bilateralmatters.org/userfiles/file/6513563578.pdfIn PDF document text
    • https://hoangphatdanang.xetnghiemadndanang.com/uploads/image/files/laxun.pdfIn PDF document text
    • https://www.hemingway.bg/app/templates/js/ckfinder/userfiles/files/50807368074.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/3504772268.pdfIn PDF document text
    • https://seedcambodia.org/htdocs/cljr/data/files/zurazavuda.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/22139428332.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/49883904097.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/a72d97495760e86d81db5e1f479852b9/37898364715.pdfIn PDF document text
    • http://rebornfair.com/FileData/ckfinder/files/20210919_010A2333B0E95105.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/61562170873.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/54581664386.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/4988476086.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210920201347.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=organic+chemistry+synthesis+practice+problems+pdfPDF 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_off0000b35e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB35E 16300 bytes
SHA-256: 720998e2745d5684a62288086bc2a00d6b39cb1e7d002cc2185d75f8933b83ba
font_01_sfnt_off0000dcee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEE 11344 bytes
SHA-256: 56ace64a3a06250ea1248a8c0a102ea6dc1b6ec32c32ecb45dc0a294eb33d377
font_02_sfnt_off0000f715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF715 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1