Malicious PDF — malware analysis report

Static analysis result for SHA-256 66a53e30451fab4d…

MALICIOUS

PDF

96.2 KB Created: 2021-09-12 09:19:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4973668e282f71921b7f6ae754b19b0c SHA-1: 7cfa718945d82bb15342282b977c692860eb064a SHA-256: 66a53e30451fab4d0ed4307646f4b84c8c87e3dc47b01e5a4a7b19b60ffdc2dc
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm and a callback phishing lure. The document body is heavily obfuscated, but the presence of numerous external URIs and the 'SE_CALLBACK_LURE' heuristic strongly suggest a phishing attempt designed to trick the user into calling a fraudulent number. No scripts were extracted, but the PDF structure itself likely facilitates the redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://allytemp.ru/uplcv?utm_term=streaming+infinity+war+end+game PDF link annotation
    • http://jarauwerdaenzn.nl/userfiles/file/lunilofusijujixu.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/42358096536.pdfIn PDF document text
    • http://3e3i.com/UserFiles/file///lijekuvuretevozi.pdfIn PDF document text
    • http://tovicetour.com/FileData/ckfinder/files/20210912_87D5C2CC39130126.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210904/files/20210904010044.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vurejojomegosubugudu.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/gedulekij.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/48018835888.pdfIn PDF document text
    • https://tradingphrases.net/userfiles/files/21327492971.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/12762387181.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/zufatedovunetutikafat.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210906181322.pdfIn PDF document text
    • https://kingdomofgodmn.org/userfiles/files/degefax.pdfIn PDF document text
    • https://coaching-jk-academic.com/ckfinder/userfiles/files/pomuxevowozutanono.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/84064975038.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/jesunajutigiteze.pdfIn PDF document text
    • https://cobrawire.com/userfiles/files/20524357728.pdfIn PDF document text
    • http://ore-processing.ru/d/files/86535083494.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/narofugudimakorepedukezul.pdfIn PDF document text
    • https://habibitours.com/ckfinder/userfiles/files/dujili.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161306043527e9---xamunew.pdfIn PDF document text
    • https://umiyawoodworks.com/fckdb/userfiles/file/96161255224.pdfIn PDF document text
    • https://majubesar.com/contents/files/41727752444.pdfIn PDF document text
    • http://lmalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vivoxagajixetoxefop.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_off0001144a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1144A 17976 bytes
SHA-256: df3b239a3d4af4a6ceb45bd6b55e158cceaf2d736fd3165a24ecb8b9191c5431
font_01_sfnt_off00014306.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14306 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015b1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B1D 10636 bytes
SHA-256: 50fd4afb1cdaadca96a0137e201f48b08220e047f36aa39959b698121678e937