Malicious PDF — malware analysis report

Static analysis result for SHA-256 23fcb1ba0c4c8fc5…

MALICIOUS

PDF

94.4 KB Created: 2021-06-29 04:11:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f36c32514d1bc1c21833d109ea266b1b SHA-1: 12d9f1b27c7403570f2730c4b9662303f8e96aed SHA-256: 23fcb1ba0c4c8fc50a0e461411d5e4e6cda831aa8dde6a15f9990069097e3ad5
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised CMS upload directories, suggesting a phishing or redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The presence of multiple external URIs and link farm heuristics reinforces the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a923ee64842---zumopisowenowumeje.pdf
    • https://argentinaproduct.com/ckfinder/userfiles/files/wedulugo.pdf
    • http://euro-ex.com/73748407393.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/ca95fe7a69827d102d696e70d1568699/75508654845.pdf
    • http://massimomoroni.it/userfiles/files/lonoludijujuraxavozow.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e60e4b4c64---2353045659.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095dfbc6d411---wagilanudibimusukizefi.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/79l09jp1gcv81kp6ql1c3nc3in/nojubemotoviwesanajalelo.pdf
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/6v1n8ni9ms0u4vhf01cn1474ih/74861363018.pdf
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/f8f5200de9ae8751a2a6934271f219b6/zaxig.pdf
    • http://profil-metall.de/content/uploads/file/99954150733.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088807fde467---bogujufewo.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/ckr4glsu69bf0js01n0dvikjlh/67687181155.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/1d7a4c1ef9cb467c6f6a36f1f7bb7e88/960073500.pdf
    • https://phuketwebstudio.com/ckfinder/userfiles/files/46270204421.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160841704f3142---dopegutizipax.pdf
    • http://suapaiatuipelehakefamily.com/clients/80707/File/94264108765.pdf
    • http://paillasse.hu/userfiles/file/nazutoke.pdf
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2cb3be4b63---36894096700.pdf
    • https://angelsstaff.com/uploads/file/81358020932.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=king+baby+syndrome
    • 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_off00010f3f.bin
a84ca23eabcb822eafd343f97d7b5e47ea1b10d70621108d18497f7f44fcdb33
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3F 17484 bytes
font_01_sfnt_off00013cc7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CC7 16792 bytes
font_02_sfnt_off000154de.bin
264536b33fb31f3067f87db12296ae111ca15d02568a1019361a367222196a2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x154DE 10692 bytes