Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8535308d12f45f8…

MALICIOUS

PDF

75.5 KB Created: 2021-09-11 06:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e0613560d2780dae53f7f69a49867f8f SHA-1: ffac3cda047e3b59d35cc660539bf778d553a532 SHA-256: c8535308d12f45f8881f5d4878bccdc7c1941b1107bf914679ce7b05b9ea9dc9
146 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a callback phishing lure. The document body, though heavily obfuscated, contains embedded URLs that point to disposable hosting and link farms, suggesting an attempt to redirect users to malicious content or phishing sites. The presence of multiple external URIs and the overall structure indicate a malicious intent to deceive the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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
  • 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://nomylo.ru/uplcv?utm_term=chacha+chaudhary+comics+in+english+pdf PDF link annotation
    • http://asiadomainstore.com/userfiles/file/birosijevikepuki.pdfIn PDF document text
    • http://vakaruinzinerija.lt/userfiles/file/53522878454.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/59524886503.pdfIn PDF document text
    • https://techinnsrl.com/writable/public/userfiles/file/dosexanagakanitipazuluvog.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138215131ad5---21951925259.pdfIn PDF document text
    • https://groupekineconcept.com/userfiles/file/7568971763.pdfIn PDF document text
    • http://jinistudy.com/_UploadFile/Images/file/48299207760.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/46588038816.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372198dd3cb---51881594167.pdfIn PDF document text
    • http://puisan.ru/uploads/file/kasigofubo.pdfIn PDF document text
    • http://noospc.ru/SITE/files/editor/file/95911603431.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.com/userfiles/file/97350458050.pdfIn PDF document text
    • https://jagamimpi.net/contents/files/35136554323.pdfIn PDF document text
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/21732174797.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/96022938394.pdfIn PDF document text
    • http://orel-trinity.ru/sites/default/files/file/votunokudobuxede.pdfIn PDF document text
    • http://progettocecinacuore.it/writable/public/userfiles/file/vesuvewolivapibakuno.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/48722049267.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/zuwomomatuv.pdfIn PDF document text
    • https://rinducm1.com/contents/files/werivamibiguredazixe.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/tonos.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/dirotizawizexiwa.pdfIn PDF document text
    • http://wonikqnc.com/upload/editor/file/1631127631.pdfIn PDF document text
    • http://www.nachtruhe.info/up/files/71497341521.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_off0000c1cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CD 17440 bytes
SHA-256: 44b652975ccce3976ad8534330c1cd73cff9054d538e5bb6dad76a914cf3f9a3
font_01_sfnt_off0000eecf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECF 11216 bytes
SHA-256: b49143b74b9aba90235fa5adb878929e700b997a987aee51c77958696c012225
font_02_sfnt_off000108af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1