Malicious PDF — malware analysis report

Static analysis result for SHA-256 a21cb9bb270fab4a…

MALICIOUS

PDF

139.3 KB Created: 2021-06-27 13:10:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f41d6393363faee0f00d25baba837fbf SHA-1: 26aa29b244015ff77a1e85eeca2a65406a4236c9 SHA-256: a21cb9bb270fab4a2af2df36bfd19cc935f7aa6d97850d6ef7da39f07bd38b2d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. Although no scripts were explicitly extracted, the nature of PDF link farms often involves embedded JavaScript for redirection, hence T1059.007 is included.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9761

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 https://tylbm.com/Upload/ckeditor/files/dilutefakapukupejul.pdf
    • http://ahcxdq.com/uploads/file/290224105534.pdf
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/6o0lauo866eke5ch0669l5qn84/18715977749.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ff477b3f8---97689187719.pdf
    • https://pasarantogel2.com/contents//files/gokewerubelifexunowinowo.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/ebcb9a135de42b92a3a5ca3ef5d9a152/54882140809.pdf
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/2f1cea9d70025a43e2da632c229d9296/jebixelosetij.pdf
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/1fb050a7e10b64ac71d944ac7fdb4a51/zuzixowodulapijuju.pdf
    • http://lsbwg.com/ckfinder/userfiles/files/20210608/1314047857.pdf
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/a10vc32a4vrhndefrqmckrnfr1/saxololuzuv.pdf
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9789af1e1---33359865824.pdf
    • https://datatech-int.com/userfiles/file/zeserutewijolemuvixaje.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/3dba06eec74f3249115163eed9093ebf/23966922352.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bc3ef24a9cd---45824573142.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c32eda1547b---98161069550.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/4b30dc86a564e3bdc58adfcb1090d5a2/13761991091.pdf
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/5j7n06arnn0dqmv38gvgn5iliu/limitimilovibawibexoted.pdf
    • https://whiteelephant.co.in/wp-content/plugins/super-forms/uploads/php/files/2550ae0b0e83102e463e9bb19fa1b92b/javukodevodopuju.pdf
    • http://usmleworkout.com/files/file/tarak.pdf
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c84f678ba9a---32630837838.pdf
    • http://www.hangmandigital.com/files/file/35265533798.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607c618eea808---95127614230.pdf
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/96d70afcf7ecd715c2b506a91e32d1af/mutekuravawofofid.pdf
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/44494ae12dfff03bbb39c0a71c150b0a/vobijizudo.pdf
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/f13d2c1cb3a7c6d7b5f74151d5c7407c/9540836392.pdf
    • https://jodhpurtravels.com/nbloom/fckuploads/file/69379807554.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=optical+processes+in+semiconductors+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_off0001b45b.bin
19d6277e597b240e24a6f19801d2483fb54ddc9beecb81b010c51cc4d406a61a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B45B 21772 bytes
font_01_sfnt_off0001ec0a.bin
989613c8429b92b4caabd529c05977340223d8cde281e2a90af380c9478a5664
pdf-font-stream PDF embedded font (sfnt) at offset 0x1EC0A 10908 bytes
font_02_sfnt_off0002054c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x2054C 16792 bytes