Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b4dbf4810809c8…

MALICIOUS

PDF

87.9 KB Created: 2021-07-03 10:58:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 30ffdafe0e014efbbd89ef4afdb36ca1 SHA-1: 6771eed8e707cb16ef282bbdfb8073f2d0aba79d SHA-256: 21b4dbf4810809c85c44a439907809e9008ec5a87f0b822db1c1ab54e542e528
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing campaigns that leverage link farms to obscure the true destination. No scripts were extracted, but the presence of embedded URLs and the overall structure point towards a spearphishing attachment attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://catamma.ru/uplcv?utm_term=iron+rich+foods+for+vegetarians+pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddcf33495ae---kapevizararexigemiw.pdf
    • http://0-50.ru/userfiles/file/kuwatesuxozasep.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/d8f943dffb4b9fc5a127c49292303642/65016600760.pdf
    • https://oncallanatomist.org/ckfinder/userfiles/files/87774236882.pdf
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609136450b01c---23710566737.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160a060c186b2f---25118664717.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16070418055204---derabij.pdf
    • http://warraichmeats.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efad0729d8---minujemisu.pdf
    • http://go-pxl.com/uploads/files/55512484905.pdf
    • https://abouelhoulgroup.com/userfiles/files/mevowovuvegexijumuzig.pdf
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c777b349f78---74987358800.pdf
    • http://newabel.com/ckfinder/userfiles/files/rilixona.pdf
    • http://studiogiamberardino.it/userfiles/files/95285411033.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075039bd7f88---15665796838.pdf
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/160999fa649afc---74094088299.pdf
    • http://kassa.pl/userfiles/file/kajaxowisosafupif.pdf
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606d01668fc7c---xugejuwireluwifate.pdf
    • http://centroolosprato.it/userfiles/files/27615405481.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/1v44trld6stvimn3mn42vhbp03/90487925011.pdf
    • https://pmms-online.com/assets/file/kefuvodofusotowum.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/0cb7005f00d3d1ac546201660c2add3c/noxabifunewovimogetida.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16089b9e807f12---90051052528.pdf
    • http://www.kmclogistics.com/wp-content/plugins/super-forms/uploads/php/files/70d04623a1899d623896d1819f87bc13/86284493118.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/8dcfd91ddf08fce27f63f6224428fb2f/jivabolapuxurowadek.pdf
    • http://novichiha.ru/pic/file/51193247103.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_off0000f3f0.bin
75b06832ca66d775d843703fbe68ab74de91148215686083157a352c5d3132f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F0 16968 bytes
font_01_sfnt_off00011fd4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD4 16792 bytes
font_02_sfnt_off000137eb.bin
69e2c2f22bebfb755306482f1cb53cb0acb9cd3369c40ab3077fa0e32189d7c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x137EB 10872 bytes