Malicious PDF — malware analysis report

Static analysis result for SHA-256 71ff9596819ccf36…

MALICIOUS

PDF

79.7 KB Created: 2021-08-20 06:10:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8193a5f1537f12aee165fcebc3427ca1 SHA-1: cc1a80876146f83230e3461cc48159b2d1b07a0c SHA-256: 71ff9596819ccf366e03793b2491a9a209d5588ca5d7507d9bdf8ef8d4165954
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to numerous external PDF files hosted on compromised WordPress sites and other disposable domains, suggesting an attempt to distribute malicious content or phish for credentials. The PDF's structure and embedded links indicate a likely spearphishing attachment delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://allcreaturesinc.com/files/files/19409846498.pdf In PDF document text
    • http://qca.ch/userfiles/file/12092473535.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/r14p65et2kqrd4dra2bodsesd6/85654075842.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160c96f72efa24---8234602886.pdfIn PDF document text
    • https://et-auditing.com/userfiles/files/27814090098.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/0bb67a6a2da02c95d59dafcece504e86/62399568263.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/5283a5f41f88f70a4d87f13e08b3db7b/butojalepox.pdfIn PDF document text
    • http://krzysztofmalec.pl/gfx/fck/file/walirelirefap.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/tipanawufinek.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16119a863e4ce3---zuvutizafo.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3058aad4883a6e33bab0d9a219d86580/sozuvulobezasojewatepir.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/31d1ec53229fc8c94eef00a0150c5c13/54661179137.pdfIn PDF document text
    • http://tutek.eu/userfiles/file/42794415185.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc69095e73---numerokide.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/8a9959ec6a1318dd115d55d3a5667714/17421674778.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/279e56709db9c22f3aedd80b0fb29fa2/lumifubujekokuvizutupu.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/90691320358.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/kisitutabupafef.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff855e4661---pavodixuwagoxisalojuvid.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094afe616257---65667072014.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/pivirupixipogatij.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/69205736139.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/oio5tdm1k09guurb5855clmhe1/vikesolib.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/miboxegezedudeda.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=ncert+solutions+class+7+science+textbook+pdfPDF 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_off0000d5b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B6 16536 bytes
SHA-256: 97e95a2cd4773eb1cfc9f1efec7b6b8e3ede89e7bdd3c2189186b37d278ba0b6
font_01_sfnt_off000100a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A2 11072 bytes
SHA-256: 39324ee6c90990ca5d4279a59e5310e8b5632c5b594979cd6617eb1d3ae4f970
font_02_sfnt_off00011a6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1