Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c8bcd1da8c661e…

MALICIOUS

PDF

84.4 KB Created: 2021-09-05 20:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6192857e33cd09d2323204ca7d1b1ad3 SHA-1: f81b5f9659635b85b5ea1ee31777e1c3aa32da8d SHA-256: 81c8bcd1da8c661ec13319bfdbf31d45fbaf24ef237eabe54066c4d0258046a8
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple PDF link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://change-sexy.com/files/files/xowupezuvifikamonotijazi.pdf In PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160cc06a080698---18500898552.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/85866735320.pdfIn PDF document text
    • http://hydrogears.com/survey/userfiles/files/48518648404.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210609_CC831E5D707E897D.pdfIn PDF document text
    • http://zoo-foto.cz/userfiles/file/72197871486.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/37569071210.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/46aeaea2ef933b6630d20d96d915f00f/mezinulena.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebdd1092e3---laruroge.pdfIn PDF document text
    • http://infinity-c-t.com/userfiles/file/66872590214.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0cb9c2211---9020643236.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bab78524abe---41725916753.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/07dc0dcb5ce5fc5cd30a72ac0ff7af23/4682821472.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/12189208161.pdfIn PDF document text
    • http://thermocomfort.ca/userfiles/file/bixizijuwisuzodufuz.pdfIn PDF document text
    • http://ecandrychow.pl/Image/files/widagusadekiwefuxo.pdfIn PDF document text
    • http://artside.org/data/temp/file/38485201743.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/66596573981.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/66905843870.pdfIn PDF document text
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/pamegigaxovegemakodepuf.pdfIn PDF document text
    • http://nppgursaraijhansi.in/ckfinder/userfiles/files/17122368263.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/0aksbic2ggvn0p3pm8ph73kh5p/19721185756.pdfIn PDF document text
    • http://orlickachata.cz/files/files/segubufemajivisirozuju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=hokkaido+subway+map+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_off0000e1a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A4 18288 bytes
SHA-256: 72a9337b4c59ffc8b02d8c2fa62054519719b2d5c353109cdd3d4297673f6cf7
font_01_sfnt_off000111cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111CF 10704 bytes
SHA-256: fc30ac3ba41cb290c5695b7949dc1b2c498f6ab9edd8845f7f86c1d995514d3a
font_02_sfnt_off00012a38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1