Malicious PDF — malware analysis report

Static analysis result for SHA-256 3656e3a9e4b321ff…

MALICIOUS

PDF

81.4 KB Created: 2021-09-16 15:25:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba0f61900b4a8a1fe46c31758eebda41 SHA-1: f957fdbd38eef3feeecb03c9a8f426cd1cd1fef5 SHA-256: 3656e3a9e4b321ff4a570f5119e24beca946f9c9ea9fa21062eccff64b1f7e7d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content, such as malware downloads indicated by the 'fast charge apk' URL parameter. No scripts were extracted, but the PDF structure itself facilitates the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://inwebjor.ru/uplcv?utm_term=fast+charge+apk
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613226e243aee---dijemo.pdf
    • http://shengnabei.com/uploadfile/file///2021090610142949.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313b951313e---17926324380.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16141d99ca4c38---10347009518.pdf
    • http://pastadimatteo.com/ckfinder/userfiles/files/94674275398.pdf
    • http://fsgzb.com/upfolder/e/files/20210915210238.pdf
    • http://delfosventures.eu/userfiles/files/44413922698.pdf
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/busemafavokajibez.pdf
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/98002047186.pdf
    • http://boschvietnam.com/files/usersfiles/files/tajojilariw.pdf
    • http://bushurov.ru/images/files/zekelolomoviliribavax.pdf
    • https://comobrew.com/newsite/images/user_uploads/file/bilubak.pdf
    • https://melz-feu.ru/upload/74775423891.pdf
    • http://baove247.org/upload/files/sibisutopitoge.pdf
    • http://www.cottagegrad.ru/files/file/misevanefexonizi.pdf
    • http://keacg.com/upload/files/roderagetamom.pdf
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131da9a3b8fd---46269022522.pdf
    • https://arbormaster.net/uploads/files/gowosojuwufofiw.pdf
    • https://jotekonybakterium.hu/userfiles/files/pafew.pdf
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/f0474ca716b2d57ae3196133061743d2/61837394551.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161415e6f81b9a---sumugupizetemokulot.pdf
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/161302321f30ef---vetagaxiromedusalupet.pdf
    • http://zlhk.ru/upload_picture/file/77498189618.pdf
    • http://pi-consulting.ch/download/33329139279.pdf
    • 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_off0000d2bc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2BC 16792 bytes
font_01_sfnt_off0000eace.bin
6ba36972837770e8e269b35ab3db0bceeaa031d17eac3a1ef31ebe51e1843501
pdf-font-stream PDF embedded font (sfnt) at offset 0xEACE 20172 bytes
font_02_sfnt_off00012067.bin
aa46cb60567a75aa53a47731070fba5965955db728e3721087e6fffb457611ec
pdf-font-stream PDF embedded font (sfnt) at offset 0x12067 10360 bytes