Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4921fb979502da8…

MALICIOUS

PDF

74.0 KB Created: 2021-09-12 23:26:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: fa174f08d0dce663eade58a2081bde06 SHA-1: 99e64ac38c4d8d304186752d3d5b5826708e0121 SHA-256: c4921fb979502da8e0de8fe431d2991d14989315bf5752f943ac191f440c7734
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many pointing to distinct, potentially disposable hosts, suggesting a link farm designed to redirect users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the final malicious destination. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • 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.
  • 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://kfnmsz.com/upfolder/e/files/20210902082228.pdf In PDF document text
    • http://bowie.abwingsmd.com/uploads/files/jodokipifejuwufaronaka.pdfIn PDF document text
    • http://disonde.com/filespath/files/20210910194638.pdfIn PDF document text
    • http://parquet-cortes.fr/data/Files/fosexatawidetavovifumesas.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/files/nowawe.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/96674105141.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/luzetevugukikiwenanazab.pdfIn PDF document text
    • http://dekobonner.de/userfiles/file/nufekaluxi.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/60352736006.pdfIn PDF document text
    • http://hightopeducation.com/cms_uploaded/file/76320838679.pdfIn PDF document text
    • http://kutscher-customs.de/gfx/userfiles/files/38502139464.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/lubofu.pdfIn PDF document text
    • http://leicesterbiketec.com/userfiles/file/5540753559.pdfIn PDF document text
    • https://karpzbeldowa.pl/uploads/userfiles/files/70998295109.pdfIn PDF document text
    • https://luatkhangthai.vn/upload/fck/file/xukisojiganesiweg.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/1594753752.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202109082051308344.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/mejezagesod.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/jeposodidipiwexifuvejoxag.pdfIn PDF document text
    • http://gamax-moto.cz/data/dokumenty/lagunosuvitimejonijasa.pdfIn PDF document text
    • https://eliteplacementagency.com/uploads/files/xagimupowesuvivipupoba.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/fokegugepuvotazefakab.pdfIn PDF document text
    • http://esistore.lu/userfiles/file/foxofe.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/83602397362.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/kevamaga.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/63004923847.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=boruto+storm+4+apkPDF 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_off0000c1c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C7 15976 bytes
SHA-256: 0760268e3690ec0b8d2ff92182cd73e327304eeecc23c45512681a2fa2ef13f1
font_01_sfnt_off0000eafe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10315 10360 bytes
SHA-256: 858f14bd044fc0ff9b221f44f32593f557e4b5b136859473a0c9c0e9efd58236