Malicious PDF — malware analysis report

Static analysis result for SHA-256 a431d53c061ca26f…

MALICIOUS

PDF

95.5 KB Created: 2021-09-14 03:16:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 32791517beb4fbd6c640e7c8b1448314 SHA-1: cee0e6105e07639d115202522bc8109413ae31d7 SHA-256: a431d53c061ca26ff8b584c247583f2342d21ae32adc99e42ac928ce4ba96c18
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating malicious intent, including algorithmically generated URLs and a link farm on disposable hosting. The 'SE_CALLBACK_LURE' heuristic strongly suggests a callback phishing or tech-support scam pattern, where the document prompts the user to call a phone number. While no scripts were extracted, the overall structure and URL patterns point towards a phishing attempt designed to trick users into engaging with a malicious actor.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

Heuristics 6

  • 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://speckrepej.com/upload/file/vakulasuratubavop.pdf In PDF document text
    • http://wamer.org/userfiles/file/44753344193.pdfIn PDF document text
    • http://police8coop.com/UserFiles/file/21878103626.pdfIn PDF document text
    • https://www.sistemkabin.com/ckfinder/userfiles/files/34164846684.pdfIn PDF document text
    • http://puginternational.com/ckfinder/userfiles/files/korujojasawude.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/morodekunesilelo.pdfIn PDF document text
    • https://songhongresort.com/img/files/97390868778.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/32935405005.pdfIn PDF document text
    • http://hakanhurdacilik.com/userfiles/file/ruritimawafebi.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/xubezipejufula.pdfIn PDF document text
    • http://energy-labels.nl/userfiles/file/82508745348.pdfIn PDF document text
    • http://ebara.com.hk/ckfinder/Zenith/userfiles/files/11637195269.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/xefarorul.pdfIn PDF document text
    • https://rwd.webseo.tw/upload/files/fexuwujuremukavonaj.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109100431281803.pdfIn PDF document text
    • http://glovimex.com/uploads/ckfinder/files/42679303395.pdfIn PDF document text
    • https://casasholidays.com/scgtest/team-explore/uploads/files/81782610682.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133604908c53---pokibixenitemut.pdfIn PDF document text
    • http://orbitsecurity.qa/pro_mvp_tech/uploads/file/falejegorurobajoxaxef.pdfIn PDF document text
    • https://el-tall.pl/pics/file/65570914206.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/17604647206.pdfIn PDF document text
    • https://kawanmto.com/contents/files/muxexekizefidake.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/besimorameb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=see+who+follows+private+instagramPDF 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_off00010eb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EB6 11032 bytes
SHA-256: a64991bf51550f21a44cb5e93d6c628cb4716397284f1cf5b82b2b1c7a3fcc3b
font_01_sfnt_off00012843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12843 18416 bytes
SHA-256: 61d2272b0c5a238b2549cef5eaa8961efbb12d783376ddc6423988a1eb398701
font_02_sfnt_off0001582f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1582F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1