Malicious PDF — malware analysis report

Static analysis result for SHA-256 caaef2be5475489a…

MALICIOUS

PDF

84.6 KB Created: 2021-09-14 03:37:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5ba087df3f7b4b80e134baadff7f3711 SHA-1: 114f2cde7b7ef6200e835a259db3f6988592d8a3 SHA-256: caaef2be5475489a25280458e8f9bce546997a5fc4a72902a52faeace635c1b5
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript and multiple external links, flagged by heuristics as malicious and a potential phishing trojan. The presence of embedded JS and algorithmically generated URLs suggests an attempt to download further malicious content or redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://stomatoloska-ordinacija-rijeka.com/files/83729204898.pdf In PDF document text
    • http://ivankrivanek.com/userfiles/file/biguxagaripowe.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/7ddbce82ba221ddb29b7f16b1d91bf59/50523483142.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/rexevapot.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/dasugofexufebelosof.pdfIn PDF document text
    • http://w3-japan.com/js/upload/files/21049150222.pdfIn PDF document text
    • http://le-nora.com/userfiles/file/peledeb.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/51361470218.pdfIn PDF document text
    • http://patanamachine.com/imgUpload/files/noredizo.pdfIn PDF document text
    • http://immobilieninvestors.com/userfiles/file/48259257438.pdfIn PDF document text
    • http://amkchem.com/upload/files/35476342542.pdfIn PDF document text
    • http://roycraft.ca/userfiles/file/bexufafixudakojarezima.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/8081447977.pdfIn PDF document text
    • https://taksis.lv/taksis/userfiles/file/53032596484.pdfIn PDF document text
    • http://tatnhapkhau.com/ckfinder/userfiles/files/takuxoxuzufudorelat.pdfIn PDF document text
    • http://mobiliteit.nu/files/29143495542.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/30666627596.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/19235806504.pdfIn PDF document text
    • http://abwbaltimore.com/uploads/files/zavipipasabonu.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/99914641151.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/ribuwozogeribebotuwola.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf64d825a7---30064696334.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=firewall+on+android+phonePDF 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_off0000e750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE750 17752 bytes
SHA-256: 4867a6c92f1a5c5b09c1fff64b7fc38b145009e63def03127b8ecc6220d23512
font_01_sfnt_off0001159d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1159D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012db4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB4 10288 bytes
SHA-256: 1214791e36c3e3cea79ee825d2dd2848877951ad0691cc8f7b5ba57b2e64fa9f