Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9e93d330822da79…

MALICIOUS

PDF

94.1 KB Created: 2021-06-25 20:21:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 40a23262b15cea5d7d20a7bb540e7f66 SHA-1: 90379396a1cf7a6574be5277aadf076e39d83408 SHA-256: a9e93d330822da796452291687a4fef5cc3a91fd31d60ddf0724efded95b7efe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains numerous links, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the URL analysis and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://comobrew.com/newsite/images/user_uploads/file/wunagufezutot.pdf
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096946b6b099---39697158696.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f2b78eac90---20640397272.pdf
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/lqhnc81hp2ktmm847bf1ouejtm/rizimitadowufasumerix.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a47c6c40da4---texapido.pdf
    • https://free-spirit-city.eu/uploads/wysiwyg/files/mokimasijoja.pdf
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/0719346bc4653abd524b31da8242d880/7213114635.pdf
    • https://west-holding.com/userfiles/file/89284866961.pdf
    • https://soudurelausiere.ca/upload/editor/file/30390692242.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/23294514015.pdf
    • http://munsusa.org/userfiles/file/20210621220621.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/dtcbshhn8mjili3tg6kpklhnq1/wunanawolirabuzovejeb.pdf
    • http://afghansolar.com/userfiles/file/98487558139.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/8bd48ee23e21667e833c4b11819c6cb7/37454311910.pdf
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/e8127ba45a3715241c77ffc15e18e4fc/tusaximodofupezorotofavut.pdf
    • http://bruningfoundation.com/clients/9/99/99acc79c432c4c389b364f5b25189af3/File/rapafig.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a719a102168---68401371332.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160d295ff26791---53689463959.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/nji8bilau555l7j9qut5unl091/dovejivisoguzixajex.pdf
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/67bc352cce660ac62ce26ad502a9476d/77400383592.pdf
    • http://aaaexpressheating.com/userfiles/file/14593134464.pdf
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/333e86eb32dfd9d848d6d0ce79d91160/gobagaseperad.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/5f3b0dcd65c8639d15a2348c247988d5/lujonaligimix.pdf
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075c80fd1a05---sinifur.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=good+layout+for+town+hall+5
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000107e8.bin
6e53733c33c8c5488ad2c778a30ee4a50e2a1a3c21201b937fe00a7f374f3b67
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x107E8 18004 bytes
font_00_sfnt_off0000efd7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD7 16792 bytes
font_02_sfnt_off00012439.bin
12f0af89c7b163f6b6547a3d74cd4fc64060ac767f458f2b7dfb9ff81e6c0de6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12439 10532 bytes
font_03_sfnt_off00013c4b.bin
13d90bb273395c2a4a4bb97aec5b551e0357ca6a1e76c39d02ccdabc95c8e8fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C4B 17756 bytes