Malicious PDF — malware analysis report

Static analysis result for SHA-256 f2756341f34f6dbc…

MALICIOUS

PDF

68.1 KB Created: 2021-09-19 20:16:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fd88354262aa8f2e2d919717435cd373 SHA-1: 0cb36cf792961ff0d51e0e03d04af442aa75ab99 SHA-256: f2756341f34f6dbca1eb848b02d26eb81d1ec4348a4417e270f0e93be518f10e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are hosted on disposable domains, suggesting a link farm or phishing lure. The PDF structure and embedded content, though heavily obfuscated, are consistent with malware delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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.
  • 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://www.kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/28198722266.pdf In PDF document text
    • https://mclandpin.com/calisma2/files/uploads/96144142771.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/tepamatizavebebezuguga.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/luropuro.pdfIn PDF document text
    • http://danies.ru/ckfinder/userfiles/files/87998902425.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/wulebu.pdfIn PDF document text
    • http://punaide.com/userfiles/files/winovaxozaxovedodolobiget.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/lebul.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/67181652676.pdfIn PDF document text
    • https://comillaspostgrado.es/userfiles/file/80333248297.pdfIn PDF document text
    • http://www.petercar0937494634.com/upload/img/files/gosalulo.pdfIn PDF document text
    • https://gulfb2b.com/userfiles/file/pulaworarurowulosagorofep.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/5834358365.pdfIn PDF document text
    • https://bhopalliteraturefestival.com/mpsdp/uploads/files/guwed.pdfIn PDF document text
    • https://franciscovalles.comtraining.cl/userfiles/files/83095558361.pdfIn PDF document text
    • http://berbun.com/user_img/file/69068232462.pdfIn PDF document text
    • https://nusbetaja2.com/contents/files/mikofetebaroranaxojope.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/76705527793.pdfIn PDF document text
    • http://clinical-pain.com/pds/userfiles/files/7234216389.pdfIn PDF document text
    • http://scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/27543100639.pdfIn PDF document text
    • http://4226080.kad.tw/kads/ckfinder/userfiles/files/doxotelo.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/66512205648.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5c1a638a1---29566657378.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/sifowalonupadikukatedog.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161427e243bfa6---85565721589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=download+pb+for+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_off0000b088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB088 10320 bytes
SHA-256: 551a7b54ce3a667b73d94d36587cf7417a9a9fd0a91c6cead849953c14bf350c
font_01_sfnt_off0000c79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC79E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000dfb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB0 14164 bytes
SHA-256: 5836692524a01169bec0c964b12c1841fd970df22c7e377c62089742c1bf53e2