Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd5c62efa2052c75…

MALICIOUS

PDF

80.0 KB Created: 2021-05-19 13:43:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0aba8817854a4b44f3cf1aaf92ad2a37 SHA-1: bfb6ed716a5931f8230d708957f940552309a5af SHA-256: bd5c62efa2052c757b91d127cc993ab1ab26d9f1c23eacce3bda52fe0d4b583d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a book title, potentially used as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/nvbfqdvgopqh1vj0t3l6ba2au4/tijowelubiximitasubu.pdf
    • http://bkbflooringusa.com/userfile/abbey/file/gepirusegov.pdf
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160809f00a035b---fipigubikudekeburama.pdf
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/5benhno63tt1i3ho0pk2hrc032/93294270381.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/22230d408a00cad515a83cd2b66f0782/10696354292.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160750865c96b8---70061047840.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8b4e48567---46331766524.pdf
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/rijilewu.pdf
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/8bea1cb420db6586bf981dca25f9ecd6/nukisoxubefasetub.pdf
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/0af931399b52271c92c0de388e0db2c0/13817423694.pdf
    • http://ash-graphy.com/userfiles/file/27173369992.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607016328abe4---femokumigas.pdf
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/5aoh1ekh5lis5bva3782c502oa/92830554505.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075929f6b30a.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad56cdbfe1---runedoxizezomijajujulab.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608ceb64703bb---xisuxatax.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/b4bd246d556d05249a10cf34f5d70f16/57861854889.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/41138646302.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=raina+telgemeier+ghosts+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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ece1.bin
40d0f17b19d4d11710ed30f8445080b8a5d13cb5524fd2e57c26f47e15ec1271
pdf-font-stream PDF embedded font (sfnt) at offset 0xECE1 5252 bytes
font_01_sfnt_off0000fe8f.bin
c6e3f4f5ef6e12443952874359eeb48a6812d41c44fcf91c06062de291fc8a80
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE8F 10808 bytes
font_02_sfnt_off000122fe.bin
b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c
pdf-font-stream PDF embedded font (sfnt) at offset 0x122FE 4324 bytes