Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3e1d77a999365a1…

MALICIOUS

PDF

101.3 KB Created: 2021-07-01 19:26:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c78d1483971b0648473ed2924be3fcb1 SHA-1: 941a0f5170b604716d3ff92e4fb269b46f218d2c SHA-256: b3e1d77a999365a129e5509c33a64aadb5641a79d0649890f71c347a0584f3d9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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 http://chinoboxingclub.com/clients/36032/File/xisiwilak.pdf
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608d79b867c91---lazow.pdf
    • http://txextremecarts.com/userfiles/file/pamomejovixudumoxepafirir.pdf
    • https://narimasu-chintai.net/jcfiles/file/37550547103.pdf
    • https://sieuviet.net/webroot/img/files/kezemagosavigerobo.pdf
    • https://khanikango.in/file/tuviwelemov.pdf
    • http://burattinojatek.hu/userfiles/file/dixuniwurofunekanuv.pdf
    • http://marketypik.pl/zdjecia/fck/file/82352892718.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/35tci23m1lk5f1q111gemdjfu2/tudowedubik.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607add1830d24---pujawukolulupopawojoxiz.pdf
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/lowuvubizi.pdf
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca2aa8b458---xomoxodikeviwasasikawex.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087592614b4c---25600122956.pdf
    • http://falconartistmanagement.com/ckfinder/userfiles/files/34056715153.pdf
    • http://cfh2.com/clients/d/d2/d2a7b52150a7a947468b52e9b7560e3c/File/netemozi.pdf
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1acef96029---jimevegurununolebik.pdf
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fbc2d34ceb---26360717464.pdf
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160965da6a0532---14844337977.pdf
    • http://supermarketdv.ru/files/file/2528237282.pdf
    • http://www.alex-vasilkov.ru/images/wisdom/file/gixogavizafijiluvesajaze.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/f93ceaf582783d864207ad12c1fa4780/sidob.pdf
    • http://timeyear-v.com/userfiles/file/23985579126.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=resignation+letter+template+for+personal+reasons
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000127c0.bin
c5ee8955446b0853eef3e89f7b5a00dd49fcec0095b5297b3e2dd5ad00438a56
pdf-font-stream PDF embedded font (sfnt) at offset 0x127C0 17304 bytes
font_01_sfnt_off00015515.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15515 16792 bytes
font_02_sfnt_off00016d2c.bin
7f67c7e426e539de94920fe123bc64b50d7dadd098015705a8ef7c8330bbab0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x16D2C 10748 bytes