Malicious PDF — malware analysis report

Static analysis result for SHA-256 b52f9ba576b82f1a…

MALICIOUS

PDF

75.9 KB Created: 2021-09-21 23:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d6c7d6b01c130669fe70a4bc24277993 SHA-1: 9137dde47373daa342e3ad922388b88d090c50e5 SHA-256: b52f9ba576b82f1aad9a695acf8561d81a39c7e09a074de584a9fe914e251d50
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, indicating a link farm designed to obscure the final destination. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this is a lure for phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the ML classifier's high confidence score point towards malicious intent.

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 https://garglob.ru/uplcv?utm_term=media+server+battery+drain PDF link annotation
    • http://yameitecl.com/ckfinder/userfiles/files/20210913_135306.pdfIn PDF document text
    • http://xn----otbbfbbknchz.xn--p1ai/sadm_files/33251783069.pdfIn PDF document text
    • http://qazaqbanki.kz/data/content/files/76735624822.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/54989781099.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/nopitijofulebisekinog.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/zevusifivaza.pdfIn PDF document text
    • http://opuspoint.com/ckfinder/userfiles/files/67331423162.pdfIn PDF document text
    • http://theeultimatenetworker.com/ckfinder/userfiles/files/89369075600.pdfIn PDF document text
    • http://entrackintl.com/uploads/41717715645.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161436a33c290b---ziravipesepizumufa.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/55058446829.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16144ca92751a1---wijonub.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/munofapumilinazusanawel.pdfIn PDF document text
    • https://wasael.com/userfiles/file/bijurejelo.pdfIn PDF document text
    • http://mail-business.ru/uploads/file/4956345682.pdfIn PDF document text
    • https://grupa-energia.pl/attachments/file/86228785622.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/12818284049.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/file/93679401789.pdfIn PDF document text
    • https://lorus.rs/files/fuzalurasitodasuruvutewu.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/49739716139.pdfIn PDF document text
    • https://floridahouselottery.com/test/userfiles/file/pepomeludesejijuxowo.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/wilusimeratexinomonotub.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16147c06a45cf7---63288542558.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_off0000c588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC588 17388 bytes
SHA-256: 1226ed2d910ac4f608ae68069895f50922e40319cf9a88435f0cb0c9b6cef4e6
font_01_sfnt_off0000f2a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010abf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABF 10388 bytes
SHA-256: 23190810b19fc0a0e994b96f8e0bcea00e262376e14266c964a6e9e8f43c6c02