Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd3730135c6b6302…

MALICIOUS

PDF

86.0 KB Created: 2021-06-30 20:50:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 243e7982d8666e2b9ef179105f481caf SHA-1: c0a61cc01fb0f55b7ac867bf5a0678417174aa6e SHA-256: fd3730135c6b6302a059b67cc0b803ced7fe864518d6d94fef9f2318793f5a5c
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, likely serving as a distribution point for further malware or phishing content. The presence of multiple compromised CMS upload links and SEO-focused disposable links suggests a coordinated effort to host and distribute malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160710353a70f9---nuzarowada.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a88e4a36200---pejetalizonagarapakim.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098e96ca5b7c---88003243646.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4c1f12eb1---78031324849.pdf
    • http://446888.top/userfiles/file/47775735220.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2ddb07c94---36631360460.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/bg8jp0kboggnq8f79jum7uoit1/sokepazulexupigedidud.pdf
    • http://stepsforstarlight.ca/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/42806387105.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/khar5irh6ecoe1fan8mue2ogc3/datarulewen.pdf
    • http://findmecakes.com/userfiles/files/7365845269.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dac528704d0---43847965673.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a28334e2790---8423875167.pdf
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/7avau66vt1lhqgq9rpabcmmr1g/kinaniperawebujixaku.pdf
    • http://xn--aknmedikal-yub.com/uploads/file/kidoxofed.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1608fa0fd7c4bb---52813714955.pdf
    • https://kcharp.com/ckfinder/userfiles/files/bivixekewosewelo.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160c8cba40acdb---85691218725.pdf
    • http://alpinedelhi.com/userfiles/files/72954193433.pdf
    • http://dienmattroigiasi.com/uploads/files/vobupodas.pdf
    • http://a-kamen.com/userfiles/file/dexobibajoketo.pdf
    • http://icmasistemas.com/userfiles/files/73131454685.pdf
    • http://leebyenghun.com/new/upload/board/files/72520960867.pdf
    • http://masonhn.com/d/files/31806478113.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=candy+crush+android+1
    • 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_off0000eef0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF0 16792 bytes
font_01_sfnt_off00010707.bin
701653f50d90886ecd9a6ff348b96a52f58c35455f830385d6ee9d57e7806bd6
pdf-font-stream PDF embedded font (sfnt) at offset 0x10707 10488 bytes
font_02_sfnt_off00011eda.bin
67550d95aab32e10efd53ab3dee777ae04fb80dee273a583c5f9e7420cb3a0c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDA 16840 bytes