Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3b433876b3c8234…

MALICIOUS

PDF

90.0 KB Created: 2021-07-03 13:54:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 15f743e3edd84015944e8b3801a31080 SHA-1: f5bf2391dc62d1799f0440c0d9e6031803bd645f SHA-256: a3b433876b3c823441f7fe693d3895d1cf5bea72a47d2e767b41922b94df654d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to numerous compromised WordPress upload directories across various domains. These links likely serve as lures for phishing or to distribute further malware, aligning with the 'Spearphishing Attachment' and 'Malicious Link' MITRE ATT&CK techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160817353228db---latuwuwerunopuwu.pdf In PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609196f0b8a73---95953028112.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/10b3abcf71e3b9440a02879e599cf522/72499063521.pdfIn PDF document text
    • http://akinmedical.com/uploads/file/lefazobazikaparalilavub.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/61754918244.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/pofamivepis.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/6bblfkbk9c67mfivpdi8gci510/65050476576.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/90a09100d88dd35f215dd366b91349a9/mozakoditeneraso.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/zodef.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16203147280768.pdfIn PDF document text
    • http://htygroup.com/upload/files/44640941315.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/70072020579.pdfIn PDF document text
    • https://inverpalmas.com/aym_image/files/rudirilujitowasut.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/7cvl8tu2ordt36o4m5orkatnlf/gakojofut.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609228fee9e09---3946338982.pdfIn PDF document text
    • https://ryokanclub.com/FileData/ckfinder/files/20210701_AEF5E457CC6BC7FB.pdfIn PDF document text
    • http://westernmaki.com/uploads/files/gipufemutezen.pdfIn PDF document text
    • https://3drm.bg/uploads/pictures/files/89883803913.pdfIn PDF document text
    • http://delvalle68.com/clients/54584/File/tanetisitotajoxidi.pdfIn PDF document text
    • http://ucity68.com/clients/e/ea/ea220da86df44fb0ae3b7c8e8295ccc1/File/wowipiponejeb.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/16683261516.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/a25c112b815bb5dd7bd1ff772ae9807f/78649049037.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a18e44d91e5---10340378949.pdfIn PDF document text
    • http://casaatlantida.com/userfiles/file///90067980766.pdfIn PDF document text
    • http://jngf.cn/files/file/tapuwomifalavi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=gcf+of+21+and+30PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fcdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDC 17656 bytes
SHA-256: eaaeb4a01522bf3f3733630ad3ed3298e5a98972af2a91f5dbe74ef99edfda68
font_01_sfnt_off00012b64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B64 10336 bytes
SHA-256: 32a0aa27a6ac627d79a8dbc98a1b1396110f920a72f66177a6e93afd8e3a1a06
font_02_sfnt_off000142f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1