Malicious PDF — malware analysis report

Static analysis result for SHA-256 77e40d85e4ce0728…

MALICIOUS

PDF

69.1 KB Created: 2021-10-03 12:44:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ea9ba5d8b7bee35a674c3adf3b2adbdc SHA-1: 86b880ff366c4161d9cbc8f5a1b086ed54a67610 SHA-256: 77e40d85e4ce0728c72349758561f2f2b90b764e57e5b03d0d3b15914916f602
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high-confidence heuristic flagging a link to an algorithmically-generated URL on a suspicious domain. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. The document body is unreadable, but the presence of many external links suggests a lure to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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
  • 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.
  • 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://wastran.ru/uplcv?utm_term=the+rime+of+the+ancient+mariner+part+3+line+by+line+explanation PDF link annotation
    • http://eros-arena.com/eros/userfiles/file/kemiranofegefijun.pdfIn PDF document text
    • https://megalightgroup.lv/uploads/files/36440550795.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/11135458796.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pojuzexi.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/52559942751.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/ruziterekebetawuj.pdfIn PDF document text
    • http://modern-pro.ru/files/file/44574785706.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/11911057572.pdfIn PDF document text
    • https://aynadakikemalizm.com/resimler/files/30285068049.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/nisefinakogiposiv.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/91824245898.pdfIn PDF document text
    • http://gachbinhduong.com/upload/file/xobob.pdfIn PDF document text
    • http://it-hair.com/userfiles/36180961421.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/161533ba43dd06---85095507268.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16152bd323eb32---69847833460.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/lafozogakutumibuxos.pdfIn PDF document text
    • https://stvorki.ru/files/file/zesobilosomosejoworazerez.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/xudenerite.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/misaborasovolefurep.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/72285440661.pdfIn PDF document text
    • http://weldingplaza.com/files/file/mirowev.pdfIn PDF document text
    • http://omegapizza.net/uploads/files/sifumenofa.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_off0000acd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACD2 16040 bytes
SHA-256: 3a2a5e83ac1702894935e5541470e822cf3c3f9b88e5fe3b84af363824bae221
font_01_sfnt_off0000d51b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD51B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED32 11068 bytes
SHA-256: 07a80a9705ffedf0bfccc875f439bc08fb9d215de7e77f534f82c57c6716d3f5