Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1a50c134502111c…

MALICIOUS

PDF

90.5 KB Created: 2021-09-18 03:06:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fea6f93c86dcd83156582b702bcb1a85 SHA-1: 2e26a6c659da185f0fcc008ca80f148ccef364f3 SHA-256: c1a50c134502111c6876cd43aeeed27c71650946980ad30a33e1ad7220354023
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier flagged it with high confidence. It contains numerous external URLs, many of which are part of a link farm on disposable hosting, suggesting a phishing or malware distribution attempt. The malformed stream length heuristic indicates potential exploit activity within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9923

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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 https://irlanc.ru/uplcv?utm_term=acoustic+guitar+tuner+apk+free+download PDF link annotation
    • https://aspirans.com/files/file/zidajaripidu.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/73717312869.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/51435251443.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210918_DA13A11AD9A1207C.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/94036139411.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/kakeweboxazerov.pdfIn PDF document text
    • http://casaperugia.fr/userfiles/file/pufesalavomujapiwikivoman.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/radesagukavofu.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/12786353617.pdfIn PDF document text
    • http://tycoonmedical.com/userfiles/file/mexusotuv.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c1932fcd9---gafabozuwezoza.pdfIn PDF document text
    • https://webdatedepot.com/userfiles/file/88523650220.pdfIn PDF document text
    • http://controldellaves.com/app/webroot/arxius/file/27056821208.pdfIn PDF document text
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/delezopujisomumoxoxo.pdfIn PDF document text
    • http://timocomputer.cz/files/file/6710157714.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/37636267896.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/83696bc359a3a10a1b87dcab39edcbff/53943672742.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/90935122456.pdfIn PDF document text
    • https://sinarlangit1.com/contents/files/guzofive.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/zelikodafajulagutixixave.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/53603526917.pdfIn PDF document text
    • http://euroteam.vn/ckfinder/userfiles/files/4338388461.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/61345943379.pdfIn PDF document text
    • https://gamedunyasi.com/calisma2/files/uploads/70569248867.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/51079533481.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A4 11056 bytes
SHA-256: c028ab3d2d85f37d22a1b93e5cfe3e6136944c255a2a2ceab157eeacdf87259d
font_01_sfnt_off0000f16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16A 23136 bytes
SHA-256: 6b0581de0d8a284361363d8fe9be523f94d74830ce15d3a3b1bddfe75419724a
font_02_sfnt_off00012af0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00014301.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14301 16456 bytes
SHA-256: e4164da97a0c71592dd8aa170c333043ae2c4bc80799512b36236b39fdeee209