Malicious PDF — malware analysis report

Static analysis result for SHA-256 16aa3e28710b6ff9…

MALICIOUS

PDF

67.3 KB Created: 2021-09-17 21:21:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 292929f7a9e9a464e7b53ef176ad9d47 SHA-1: ef83eec545f09d9abf82f86a6f97a3eb14ae3fad SHA-256: 16aa3e28710b6ff9159ac26d94ce2130de3261f255038fb78b0c2f0bf6b0f623
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution, as suggested by the 'flubot android malware' UTM term in one URL. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://ketchas.ru/uplcv?utm_term=flubot+android+malware PDF link annotation
    • https://polymadeniyaglar.com/fckeditor/userfiles/file/tugoropizu.pdfIn PDF document text
    • http://ajeah-intl.org/fck_image/file/83434070433.pdfIn PDF document text
    • http://tbeaindia.com/userfiles/file/1313201913.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c3fb2b8e7b---winepowufenumulemu.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/283c11a9ad92de99209f166785ad8f23/bilufanitaxup.pdfIn PDF document text
    • https://31app.com/userfiles/file/18135666575.pdfIn PDF document text
    • https://autohausnschmidt.de/userfiles/file/99915207729.pdfIn PDF document text
    • https://isitekmuhendislik.com/userfiles/file/tetidelofa.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/88533983716.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136a43653609---82037665029.pdfIn PDF document text
    • http://bobas24.pl/Upload/file/nomikewitofodesifetose.pdfIn PDF document text
    • http://kvrhousing.com/uploads/19604179264.pdfIn PDF document text
    • http://life-homeshop.com/asset/uploads/files/52016698984.pdfIn PDF document text
    • https://albertoangel.sinecsas.com/ckfinder/userfiles/files/20852943388.pdfIn PDF document text
    • https://aynispirit.nl/userfiles/file/dewojep.pdfIn PDF document text
    • http://newdimension.su/userfiles/file/gorale.pdfIn PDF document text
    • https://psystat.net/candyticket/uploads/page_images/files/fipukajovaruvefuliwojagav.pdfIn PDF document text
    • https://bagstyle.uz/images/file/xagidexupupi.pdfIn PDF document text
    • http://rkenterprisesonline.com/FCKeditor/file/86773086312.pdfIn PDF document text
    • https://renewone.de/files/kokipanuvupirij.pdfIn PDF document text
    • http://an-professional.ru/img/files/file/wijaso.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_off0000ab80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAB80 10544 bytes
SHA-256: e9c9ea2ff4394ec867cd7f8dc44f2ec45d718b22b940af871d4b4768ec224492
font_01_sfnt_off0000c381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC381 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000db93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB93 14632 bytes
SHA-256: 47f1c4b00f877487e4698fba09e5c042a0abfeffc50344dada33947ccd481cb5