Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac674a8f073518c2…

MALICIOUS

PDF

78.0 KB Created: 2021-09-23 19:21:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1925b6645e6d31e873bb071caff69ada SHA-1: 90011df8b041525c17fffe82646fb96bf2737f47 SHA-256: ac674a8f073518c2e2d4b95e00ab9c1d965d81ad23e092bd2ab73b8fa8437bb2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, with one specifically flagged as a random URL on potentially disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://sziazsauto.com/uploads/files/10912308278.pdf In PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/55157044737.pdfIn PDF document text
    • https://www.koreayokogawa.com/ckfinder/userfiles/files/kaxemigesub.pdfIn PDF document text
    • https://fwstc.in/userfiles/file/konerujojuguritufobugeda.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/rukimigowi.pdfIn PDF document text
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/gixujupuz.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/lewosebem.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/27902617113.pdfIn PDF document text
    • https://biocoop.legreniervert.fr/ckfinder/userfiles/files/89659868523.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/94910593082.pdfIn PDF document text
    • http://forglass.sk/userfiles/file/88059640091.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16139921aafdcd---58947523224.pdfIn PDF document text
    • http://yonezawanet.jp/units/24250/zcycom/files/91976291371.pdfIn PDF document text
    • http://arsvet.ru/img/upload/mefimunadeka.pdfIn PDF document text
    • https://magerp.org/upload/files/revofi.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/kiwimusobiku.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/78292796306.pdfIn PDF document text
    • https://izr.fr/files/69550611008.pdfIn PDF document text
    • https://tatvan.in/userfiles/file/51800964129.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/60257415692.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/4612d443f30746e529a4798961036b03/56153854422.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=bloxburg+1+story+homePDF 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_off0000cb8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB8F 10756 bytes
SHA-256: 8e47dbe6a5718d7b8cfadd15eb627911643bcd2b5dcf93259da71c98f69ba18d
font_01_sfnt_off0000e47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE47A 17656 bytes
SHA-256: e7e8c5dd0a2ff3aaa3485b411479ee16c83cc6a5ca65144343fae23f864c6ad0
font_02_sfnt_off00011260.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11260 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1