Malicious PDF — malware analysis report

Static analysis result for SHA-256 c923ca133df1f752…

MALICIOUS

PDF

93.9 KB Created: 2021-09-20 12:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7ff305f2b439efa8f10fc8cfddbca090 SHA-1: ee4b4a7adaddfb921977efd00118e02fd4c6a05b SHA-256: c923ca133df1f7522d6363a57cb1700518c8bb5b3c03d3dd7dca8dfeb3033d56
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including ML classifiers and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the presence of numerous unknown URLs suggest the document is designed to redirect users to potentially harmful sites. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly implies it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://instit.ac/ckfinder/userfiles/files/53935638259.pdf In PDF document text
    • http://app0.linkeo.it/ckfinder/userfiles/files/fozolazuguv.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/76499813987.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210915162750.pdfIn PDF document text
    • https://corcreation.twbiz.me/data/fckeditor/files/20210915_044457.pdfIn PDF document text
    • https://ymvii.com/admin/upload/files/wefipetite.pdfIn PDF document text
    • http://xn--80adib9cjd8a5e.xn--p1ai/i/upload/files/motumutikozu.pdfIn PDF document text
    • http://aesg2edcv.handylover.com/upload/files/49895927906.pdfIn PDF document text
    • http://wingmanresearch.com/userfiles/files/82288421057.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/nexaraxixulipirufuti.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/majozokilibe.pdfIn PDF document text
    • http://trumoi-khutrung.com/upload/files/30436418664.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/6505731051.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/eb58c533ce60a34d679c2560d62e06a0/muwezixevewolusivusan.pdfIn PDF document text
    • http://yongqingtech.com/d/files/xikunasozitaber.pdfIn PDF document text
    • https://svltv.in/userfiles/files/62853500990.pdfIn PDF document text
    • http://lor-rostov.su/userfiles/files/vozupesepiromema.pdfIn PDF document text
    • https://sapporopools.com/contents/files/gakawovisemeruximi.pdfIn PDF document text
    • http://dzirerealtors.com/uploads/pisuxosejipaxiripipejus.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/51394194184.pdfIn PDF document text
    • https://smartcrm.cloud/upload/files/lomakikosatobev.pdfIn PDF document text
    • https://ladida.asia/sporlegen/administrator/imagetempfile/poxenijatifelorokivedifir.pdfIn PDF document text
    • http://neuchina.org/userfiles/file/12830783148.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b848a640eb87b182a50b10762df81156/16782940457.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=types+of+android+systemPDF 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_off0001075f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075F 19168 bytes
SHA-256: ed95576190a379c80210aa422ca0edf2c895cef1bbd2be2c99145f640914dcb0
font_01_sfnt_off0001392d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1392D 10692 bytes
SHA-256: 459fb96b66b47b2956df8c3078120d5d26860069d1f573c2287448ccc66e8bbc
font_02_sfnt_off000151bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1