Malicious PDF — malware analysis report

Static analysis result for SHA-256 88b4121df654ef68…

MALICIOUS

PDF

85.1 KB Created: 2021-09-16 01:07:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: df893d7a9a6175fd256480d462ddc860 SHA-1: c67c950dbafe28fca498b5d67bfd8db99766378a SHA-256: 88b4121df654ef68628fb3d38e5ce086013b2e7201a4eac111efa53cd9f2e9b8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a link farm with numerous links to external PDFs hosted on diverse domains. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a pattern of using disposable hosting, suggesting an attempt to obscure malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/62393043038.pdf In PDF document text
    • https://diarch.in/WYSIWYGImage/file/65364186530.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/65670374315.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/83619888301.pdfIn PDF document text
    • http://avemkz.internet-match.com/upload/files/8999754248.pdfIn PDF document text
    • https://anup.bo/images/files/87877120886.pdfIn PDF document text
    • https://peintures-descours.fr/fichier/files/95796884744.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/61445426211.pdfIn PDF document text
    • https://oddluzanie.net/userfiles/file/rores.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/52148153603.pdfIn PDF document text
    • http://hejia-ele.net/upload/jugofote.pdfIn PDF document text
    • http://bjdfszwy.com/filespath/files/20210911050909.pdfIn PDF document text
    • http://armanetti.com/images/67579083792.pdfIn PDF document text
    • http://studioesflores.pl/obrazy/file/xefovilabajub.pdfIn PDF document text
    • http://totoquynhhuong.com/upload/files/21419677732.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/43135210202.pdfIn PDF document text
    • http://yoshitomo-kokubunji.com/jcfiles/file/76522207514.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/linub.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/xikeroribikonepokaku.pdfIn PDF document text
    • https://sgicorp.com/userfiles/files/48489736086.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/105663f49843f4f3370b268002233860/57009133221.pdfIn PDF document text
    • https://priscar.com/documents/files/17416565912.pdfIn PDF document text
    • https://www.thaiahpa.com/flash/files/migewakaxugam.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/77934cc2d235befd4ed7cbc004a5888c/pofujosisugupuwek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=recovery+app+androidPDF 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_off0000e817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE817 10420 bytes
SHA-256: 29bb8ae49da7d166571abbbd2275d21f8bfc88a6febc9899937a5de59c7c87eb
font_01_sfnt_off0000ffd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E4 18056 bytes
SHA-256: 72f8b666321edc531051ba813c36fd6a94d08dc89b119fb99a9754e60525089a