Malicious PDF — malware analysis report

Static analysis result for SHA-256 61af0e5478b407e7…

MALICIOUS

PDF

99.5 KB Created: 2021-07-15 13:26:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f5cda6b1f38e4eb273383c9bf41d256a SHA-1: e320f6a5d27e70b71cfbfe5465fbe65938c50ff2 SHA-256: 61af0e5478b407e723aa5a601b810cb641b4ad9df7f8eadc06f49cec3b3d83f2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, indicative of a link farm used for phishing or malware distribution. ClamAV detected this file as 'Pdf.Phishing.Trojan', and ML classification strongly flagged it as malicious. The presence of external URIs and link farms suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9781

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://stiff.pl/ckfinder/userfiles/files/talem.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d390ced778---6887868906.pdf
    • https://luathoanghuy.com/uploads/files/gulowibuz.pdf
    • http://uctodane.cz/UserFiles/File/93501216998.pdf
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/mclud9acu17p6tq46rm3625jsb/tazenijupamomedubem.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/aqsphub9t66hn7d2j7fi9rm9j3/3273067459.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/c03c3c874dac83b87fec9aa9ccc39f11/95438651239.pdf
    • https://groupunsur1.com/contents//files/gogojijudekixapaweg.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/b97a4e77505358a229d87dff614e183e/98234560386.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdb6c29559---buzejubukofudafexiborip.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608782c83cfd0---jujedabagesijunam.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094b4ef1a894---tofiw.pdf
    • http://boldogelet.hu/media/13546264455.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd345885ce---wejelonokopalegawovirow.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/d0080715375f52d9c519cecd6e70da8b/74563693844.pdf
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a85885ab1ee---7371218332.pdf
    • http://www.urbanwaterways.info/files/2019398922.pdf
    • http://prodottoitalia.eu/userfiles/files/kukokab.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/dsr80023gi0ihiano3n4ict0ig/47584412054.pdf
    • http://ambvetsanprospero.eu/userfiles/files/97845763462.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/28a68pnp0h0jb4d3oloe391jb7/nofivoxusejegokumewib.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608cc7be88c82---xiluguvekudogas.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2f75e3c71---23032966367.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=create+form+react+native
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0001030e.bin
e1ec5950dac95ef5f9d750a4b69943a50836b42fbc48ae0f69e282c16ae08b91
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1030E 17844 bytes
font_00_sfnt_off0000f706.bin
f2c90b412b89acc14f45da67ae7b63f5c4ab7a1189a7268246f7086e116f9ee1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF706 2876 bytes
font_02_sfnt_off00011edf.bin
331514f4969037be8e5fb3e14692b19a667d36ff009cc75987a2212f982ffee0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDF 18792 bytes
font_03_sfnt_off00015012.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15012 16792 bytes
font_04_sfnt_off00016829.bin
b9021506bdb5a7d075875d59eec40b2abecd2acf6086c7873b824f3109795360
pdf-font-stream PDF embedded font (sfnt) at offset 0x16829 10380 bytes