Malicious PDF — malware analysis report

Static analysis result for SHA-256 f351cb8d5f704054…

MALICIOUS

PDF

80.3 KB Created: 2021-09-20 19:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f07c8b9c107c23add709f61e2f0997eb SHA-1: 4e1b52910cee49233bbe15d558a119d1d531da07 SHA-256: f351cb8d5f70405436b8e5240283a9a13bbdebc7dd38076bacc6b84947c87664
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to various domains, many of which are likely part of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a strategy to manipulate search engine results or distribute further malicious content. The primary goal appears to be directing users to a network of linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/18803828290.pdf In PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/nekugawetevojaxazegijak.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/39368341051.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210919_847708B91379D229.pdfIn PDF document text
    • https://delta-relay.be/userfiles/file/30701233569.pdfIn PDF document text
    • http://sherwoodonionfestival.com/ckfinder/userfiles/files/10108861561.pdfIn PDF document text
    • http://hadt.vn/upload/files/xamuza.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/titazudalofos.pdfIn PDF document text
    • http://someteme.com/archivos/_20210912095515.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/84531049879.pdfIn PDF document text
    • http://moonlightmontessori.com/upload/files/navazafukurajo.pdfIn PDF document text
    • http://nikunjfoundation.org/ckfinder/userfiles/files/nonexakudivatarej.pdfIn PDF document text
    • http://asztalosweb.hu/userfiles/file/97004757515.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/guwozagikoniregotegajazak.pdfIn PDF document text
    • https://ilexgold.com/app/webroot/files/userfiles/files/73098729454.pdfIn PDF document text
    • http://abnicum.ru/files/file/venafasapakiliwiwipot.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/45509226448.pdfIn PDF document text
    • http://synfarm.com/upload/files/75336650199.pdfIn PDF document text
    • http://dagmare.de/userfiles/file/mipunanisemilutame.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6ce2d03b4---migakozaxuwexawonafiw.pdfIn PDF document text
    • https://spvi.cn/filespath/files/20210909212658.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/kozukufifijorawabanij.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/zoramijisibavobok.pdfIn PDF document text
    • https://labelmarket.pl/data/file/joxidesuderitisujewagig.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/28555699563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=outgoing+ringtone+kaise+lagaenPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00010464.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x10464 16444 bytes
SHA-256: fef1f0d5b59f17b2736f5c557135e9257f6c953ac1814adb66ece7d53c6baf94
font_00_sfnt_off0000b949.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB949 19676 bytes
SHA-256: 7a027c4757eabbbf0a40083f3a9b14d256521985c37ad7c64e606c9680960a36
font_01_sfnt_off0000ec5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5C 10500 bytes
SHA-256: 794dba5e675dcfe8efa93542df3f329d8eafd6b649e274500971dfb35ee62047
font_03_sfnt_off00011b30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1