Malicious PDF — malware analysis report

Static analysis result for SHA-256 438d28d0ec331285…

MALICIOUS

PDF

82.6 KB Created: 2021-09-11 07:07:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: bc499ad4ce4b5ef6109515e76f54cf13 SHA-1: 2e87d378f36260137360671e5c99748c0da00d16 SHA-256: 438d28d0ec3312854a7e0c3d5e71fcaf18c834d6f921b3004093a4a0ed46e73f
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1539 Steal Application Data

The sample is a PDF file flagged by multiple heuristics, including ML classification and ClamAV, as malicious. The 'SE_MFA_LURE' heuristic indicates the document is designed to trick users into providing sensitive information like one-time codes or MFA approvals, consistent with credential harvesting. The presence of numerous external URIs, many hosted on disposable domains, further supports a phishing or credential theft objective.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • MFA / one-time-code harvesting lure high SE_MFA_LURE
    Document asks for a one-time code, authenticator approval, or MFA confirmation — consistent with credential phishing kits that steal session tokens or abuse multi-factor authentication
  • 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://exihomes.com/userfiles/files/33058618834.pdf In PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/volovagogupot.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/makiketegijotumewasotiw.pdfIn PDF document text
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/14472958735.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/31109385445.pdfIn PDF document text
    • https://strategieb2b.ca/userfiles/file/41662804863.pdfIn PDF document text
    • https://pagodatalk.com/_UploadFile/Images/file/22070189713.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161369c6d3c37e---81200433313.pdfIn PDF document text
    • https://pustelnik-budownictwo.pl/ckfinder/userfiles/files/wafivipelugirimalarapof.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/74463794619.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/ranugomawepalarutunudidom.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/96063394344.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/53556629289.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/ce712ff0712603626f587e9f25a223c8/tolezusafanarabumiw.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/21930961900.pdfIn PDF document text
    • http://france-ex.com/images/blog/file/mofugiluranifo.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/tupopasoz.pdfIn PDF document text
    • http://ilovechardonnayhills.com/userimages/xirenupexoni.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/17889567657.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/zuxeruv.pdfIn PDF document text
    • http://ocean-ex.com/images/blog/file/2408215771.pdfIn PDF document text
    • http://h-st.nl/bestanden/files/64264153319.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/94254859018.pdfIn PDF document text
    • http://freeware-software-download.de/uploads/editor/file/dofuwazepemezi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=play+apple+music+on+androidPDF 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_off0000db09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB09 18792 bytes
SHA-256: 5143a3f809fbb8230949a7b8dc90482511d9c7bcf76ad9381ae647a218548129
font_01_sfnt_off00010c11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12428 10792 bytes
SHA-256: a340da0845354220c9a1077f3de5e23cd7432bd8ee4784406a9385b74ce80ddc