Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a4d6a3daa9df94…

MALICIOUS

PDF

82.5 KB Created: 2021-09-18 17:23:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c44fcbe7e3946a06aa29f0278850efaa SHA-1: e859e0ced2ed197c6e2af50ebeb48ddc1a9eed01 SHA-256: 16a4d6a3daa9df940dfde7a89d03cdf73bf4ac09cac60a76b873c5730e98c10d
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external resources, many of which are hosted on disposable domains and appear to be part of a link farm. The 'SE_CALLBACK_LURE' heuristic indicates the document is designed to trick users into calling a phone number, consistent with phishing or scam tactics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or a trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://falconfam.com/ckfinder/userfiles/files/84660508321.pdf In PDF document text
    • https://gastriklandsbf.se/UserFiles/files/kologojitewas.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///2325741332.pdfIn PDF document text
    • http://obkladacstvikolar.com/content/8842078691.pdfIn PDF document text
    • http://congseng.com/uploadfile/files/58283224837.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/18961361024.pdfIn PDF document text
    • http://aadcnfgl.netsociality.com/upload/files/kivav.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c05b35045---zutibowifaji.pdfIn PDF document text
    • https://millinerandassoc.com/files/file/97413132009.pdfIn PDF document text
    • http://caopump.com/admin/userfiles/file/76010685091.pdfIn PDF document text
    • http://srcchaika.ru/files/uploads/files/nozilabasikazadux.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/jiresomagobis.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/gefapedawote.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/5631148997.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/xibasemamufedomu.pdfIn PDF document text
    • http://crestviewshopping.abwingsmd.com/uploads/files/76131458949.pdfIn PDF document text
    • http://www.flamanville-76.fr/upload/file/kofuwevixivi.pdfIn PDF document text
    • http://lrm.mcdonalds.ua/ckfinder/userfiles/files/biwajevumetowewaxobe.pdfIn PDF document text
    • http://dentalcenterstudio.it/userfiles/files/87346162342.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/vanirukavukikidirazivowo.pdfIn PDF document text
    • http://rs-entp.com/upload/file/tovemodo.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/95306947138.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=reduce+video+size+without+losing+quality+androidPDF 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_off0000dce3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE3 17236 bytes
SHA-256: a0c484e1833815802ef183280d50522eb217485183eb8991721d04fd2295f859
font_01_sfnt_off000109e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E5 11268 bytes
SHA-256: 0be727ce0b9341c220469fefafad3da1d6ded5179bf4bfffa390ede762d9c735
font_02_sfnt_off000123e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1