Malicious PDF — malware analysis report

Static analysis result for SHA-256 21e9ee01f0508d19…

MALICIOUS

PDF

81.9 KB Created: 2021-09-18 11:50:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a58025b208ea95e46572c9fc68be2b73 SHA-1: 41bf530d026f612dcd69546de9d2a3123065f672 SHA-256: 21e9ee01f0508d194c240052a4e5e83d49f19aa5061bc95ca33972f3b193447e
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF with multiple heuristic firings indicating malicious intent, including random URL links and being part of a link farm on disposable hosting. ClamAV also detected it as Pdf.Phishing.Trojan. The presence of numerous external URLs suggests a phishing or malware distribution scheme, likely delivered as a spearphishing attachment. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://chcial.ru/uplcv?utm_term=love+nikki+dress+up+mod PDF link annotation
    • https://ikansambel.com/contents/files/pofini.pdfIn PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/sunedexedugokit.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/jibafitubo.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/ritajakutegokefinipipit.pdfIn PDF document text
    • https://ita.kru.ac.th/ckfinder/userfiles/files/92214821444.pdfIn PDF document text
    • http://xn--lv0az70cxar.tw/uploads/files/202109091552487784.pdfIn PDF document text
    • https://bwhe.in/ckfinder/userfiles/files/22114802189.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/021042505672.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/64380642107.pdfIn PDF document text
    • http://cmtsport.com/pliki/1923326861.pdfIn PDF document text
    • http://aurora-c.jp/files/files/89262575155.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/55920782790.pdfIn PDF document text
    • http://akbarestate.com/survey/userfiles/files/vavukujedabak.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/mapetigojerade.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/pudotibupeberoxoriv.pdfIn PDF document text
    • http://transchem-tech.com/Uploadfiles/files/84677071889.pdfIn PDF document text
    • http://npi-management.com/ressource/site-image/files/33333906975.pdfIn PDF document text
    • http://pazarziraat.com/userfiles/file/dukedeja.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/nufebu.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/xivijezow.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/zokesiwobopukozobodoso.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/6c99cd6c4a728ffca8819497e27668b1/jagesepivapotuxudi.pdfIn PDF document text
    • https://izyskately.ru/foto/ck/files/xexegimogox.pdfIn PDF document text
    • http://ottuk-e.org/userData/board/file/xepabopiragowixorulasoli.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614296e9e2f91---70219619466.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d947.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD947 19144 bytes
SHA-256: 2d10ab0c3e35d4f406aa462d3902570275a1d8fde5996380a67d2ce6dd8ac87d
font_01_sfnt_off00010ab3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB3 10460 bytes
SHA-256: 14c2d003c9bedb377027221e7232f1acbec30c81de961bac70bef46b5f395bf7
font_02_sfnt_off00012266.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12266 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1