Malicious PDF — malware analysis report

Static analysis result for SHA-256 553fa47a4b37c661…

MALICIOUS

PDF

82.7 KB Created: 2021-10-24 00:34:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 8d320147fb446e181ec325218e2650e1 SHA-1: 38be036b16a94ec07ac5e363a5b590d432b3c8f1 SHA-256: 553fa47a4b37c6612cf546649569f64ec824f543d2dd3111af9afe5074bc772c
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a callback phishing lure. The document body is heavily obfuscated and unreadable, but the presence of numerous embedded URLs and the 'SE_CALLBACK_LURE' heuristic strongly suggest a phishing or scam attempt. While no scripts were explicitly extracted, the PDF format can embed JavaScript, which is often used in such attacks to redirect users or display malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • 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://heichapuzi.com/uploadfile/file/57128800136.pdf In PDF document text
    • http://citty.org/images/uploads/file/119680742.pdfIn PDF document text
    • https://ccskin.com/geektic/files/26619814150.pdfIn PDF document text
    • http://teplicky-fotograf.robert-zauer.cz/userfiles/file/31636931650.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/kilesulu.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1615667a6b077d---lapilebosimunudaf.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/96154675139.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/28568452962.pdfIn PDF document text
    • https://menokatea.in/ckfinder/userfiles/files/564419017.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/pewewegimox.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/24686072757.pdfIn PDF document text
    • http://bundoreh.com/fckeditor/files/file/58353164586.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/zolojadopa.pdfIn PDF document text
    • http://www.huntsvillepr.com/files/files/perix.pdfIn PDF document text
    • http://xn--hh0b97d8is16e.com/userData/board/file/ledusavorus.pdfIn PDF document text
    • http://masonhn.com/d/files/wegisubosukezi.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/rivapowajowetepunopexipot.pdfIn PDF document text
    • http://eskuvoiiranytu.hu/blog/file/zobezigu.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210916033921488.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/47029099052.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/grmcusf3l3i81tuktfk64bdu29/mefolowukexotok.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/62548660368.pdfIn PDF document text
    • https://ivantomanov.com/userfiles/file/64079382879.pdfIn PDF document text
    • http://tlw.ro/UserFiles/file/90851611303.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/1hHberoKktI/uplcv?utm_term=mohave+county+assessor+property+searchPDF 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_off0000de58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE58 10608 bytes
SHA-256: 18c6279575346ab789856c80318eba64214114c5a4a1ac7dcc880112f820e6c3
font_01_sfnt_off0000f6a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010eba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EBA 17684 bytes
SHA-256: 1d13f80c8edc0454f1ee76224f5344431fd4b18ebcd9a485f7d5ecabf6e2d369