Malicious PDF — malware analysis report

Static analysis result for SHA-256 88cea8e53f305a69…

MALICIOUS

PDF

79.3 KB Created: 2021-09-20 16:36:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d57d3308aafe32cb4b4ea0fdd209cd20 SHA-1: 831d739838278ef3b5f35fba9f91698cd611cfac SHA-256: 88cea8e53f305a69ebcacf84001e48431c75974c589d1483a23adb1e257d34b3
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it is a link farm and a callback phishing lure. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the presence of numerous external links and the callback lure heuristic strongly suggest a phishing or scam attempt. No scripts were extracted from this sample.

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
  • 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://gustosandvic.com/ckfinder/userfiles/files/vaxak.pdf In PDF document text
    • http://thamdinhgiadaiquang.com/img/files/68709845684.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/cf9411ccc53089fbe2a41e3d169a9f27/dolukele.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/39095863182.pdfIn PDF document text
    • https://mycultureis.com/FileData/ckfinder/files/20210918_65E987D08B236BF1.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/69679520701.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/51437228504.pdfIn PDF document text
    • http://equipociclistaugeraga.com/ciclistas/userfiles/file/97932907700.pdfIn PDF document text
    • https://ciiinnovationsummit.com/ci/userfiles/files/fasumorufozuvunof.pdfIn PDF document text
    • https://eventpro-kontraktorpameran.com/uploaded/files/jegoxew.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/putesadipinejinunan.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/waxopawimigax.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/nakaj.pdfIn PDF document text
    • http://onsijsselstein.nl/userfiles/files/28674058307.pdfIn PDF document text
    • http://webinaris.blog/ckfinder/userfiles/publics/files/fupadozedulugakeg.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/merijizasu.pdfIn PDF document text
    • https://vieclamlaocai.vn/webroot/img/files/xogulomaluginuzawixekef.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/61641630188.pdfIn PDF document text
    • http://rebeccaosborne.com/uploads/39072277188.pdfIn PDF document text
    • https://solener.info/ckfinder/userfiles/files/47190955914.pdfIn PDF document text
    • https://kenadong.com/contents/files/bukofa.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161302e323504a---xewanen.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/tanozixegizo.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/dupule.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=gps+field+area+appPDF 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_off0000cd98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AA 19512 bytes
SHA-256: f21a11184004c00a48982ee6b9283ff2ef3da46ef597f2ce9e867af543aabc34
font_02_sfnt_off000118e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118E8 10208 bytes
SHA-256: 07a0b0de7c40dba434044c170bf1bf4391e8630d9dedb3b4759e3e63e5c100a1