Malicious PDF — malware analysis report

Static analysis result for SHA-256 b28ccfe0f1590684…

MALICIOUS

PDF

89.5 KB Created: 2021-08-19 15:47:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3e7e67c72013cbe3e242efbea042907b SHA-1: 228726257f07cb06b866d8676cd6ed66f6aa34fb SHA-256: b28ccfe0f1590684ed83966c84b58d5331b8972663091ff8b3d0b513011df7eb
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Numerous heuristics indicate the PDF functions as a link farm, with many URLs pointing to compromised CMS upload directories or disposable hosting. The primary purpose appears to be directing users to malicious or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9904

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://synerhu.ru/uplcv?utm_term=novela+el+cuerpo+del+deseo+cap%C3%ADtulo+42 PDF link annotation
    • http://zehanbiopharma.com/upload/files/99290426653.pdfIn PDF document text
    • http://douzonebnf.com/upload/file///67831950167.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/7777581765.pdfIn PDF document text
    • https://big-affaires.com/img/pics/files/67845075140.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/72348805255.pdfIn PDF document text
    • http://web68s.com/upload/files/37043848437.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b8c4bc69a---35545430589.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160929e4964f81---66716347870.pdfIn PDF document text
    • http://hong-tour.com/FileData/ckfinder/files/20210801_53453A30D30DA24B.pdfIn PDF document text
    • http://keystoparadise.com/userfiles/files/17880600708.pdfIn PDF document text
    • http://hocikto.info/userfiles/file/xanogegetagod.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160766dbcebd2b---44730862311.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/5fc29f3585a8c49ae84b4d7632f1a564/dumazo.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/3786922941836ed88845a9d0d365a6c6/86988284720.pdfIn PDF document text
    • http://nensi.si/upload/file/nabawadununukirelujekupuf.pdfIn PDF document text
    • https://atraba-holding.com/userfiles/file/detiresijefubirutawabavom.pdfIn PDF document text
    • http://fazendasaojudastadeu.net/fotosempresa//files/29455630329.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608889055a08e---wojavonejazubenumidawi.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160862f533b128---nenun.pdfIn PDF document text
    • http://xn--or3bi2da319p.com/upload/fckeditor/file/18178316278.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/vezonobojikutexejasut.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607feea36e8b2---93929370033.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/lofojofobuligasuwemufil.pdfIn PDF document text
    • http://wtmongolia.com/materials/file/52749669168.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/c3c49af4139d933f7865b861764c18f4/gibibematakafa.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/6702683846.pdfIn PDF document text
    • 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_off0000ec43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010455.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10455 23472 bytes
SHA-256: 173b136fe711662f839cca0d16e467d1079b3a0fb1947e0fcd3bb13049974874
font_02_sfnt_off00013d12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D12 10716 bytes
SHA-256: d21e0578be383736fca33728582708efd9d24d22e53feda24a7d59aba4a4882d