Malicious PDF — malware analysis report

Static analysis result for SHA-256 871f12e36812ee19…

MALICIOUS

PDF

94.5 KB Created: 2021-09-11 07:25:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: af321bbeded78dd5d1b85830f046e4d3 SHA-1: a1fec5a44398d4dba16c6296c689ae147fedccd9 SHA-256: 871f12e36812ee194e5beff0c78eebcc65f4afe26583b5264d6c49ceb418d390
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The PDF structure itself is also flagged for containing duplicate objects, a common obfuscation technique in malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://crysiq.ru/uplcv?utm_term=sao+war+of+underworld+part+2+ep+3 PDF link annotation
    • https://e-ssuances.com/ckfinder/userfiles/files/benidejinokisumodatixara.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/romukuwilobinivumamibimek.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/povoronakofudaxitorena.pdfIn PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/2348357856.pdfIn PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/21582238983.pdfIn PDF document text
    • https://stmpallet.com/ckfinder/userfiles/files/30676943422.pdfIn PDF document text
    • https://zakarpattya-tour.com/upload/ponulamerej.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/8sbojar56qgngbdsar0qm9t3g7/rubadafaxik.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/53740476047.pdfIn PDF document text
    • http://x-site.by/upload/editor/files/fajukiwaxaganoroxipin.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-6/20210906002237285319.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/xeropazitadefajinex.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/safesakusuzorogemugife.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/11509297700.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/telamizukirudodaxevirus.pdfIn PDF document text
    • http://finadev-groupe.com/userfiles/file/lovasit.pdfIn PDF document text
    • https://marbeyoyun.com/calisma2/files/uploads/59589621054.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/rekufafuxumikel.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/pizasupivogelojew.pdfIn PDF document text
    • https://mylin.in/ckeditor/ckfinder/userfiles/files/gonoxox.pdfIn PDF document text
    • http://mientrungland.net/uploads/image/files/48706562802.pdfIn PDF document text
    • http://jnmindia.com/outscapes/admin/ckeditor/uploads/ck/files/sogapotosa.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20210903_5C85EB57EBB2B1EC.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_off0000ffd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000117e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E9 22792 bytes
SHA-256: 4fd7f712aa2f92b34ae02b288afdf38873c622b136cb5760c485f15d2e9c4eb2
font_02_sfnt_off0001533c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1533C 10784 bytes
SHA-256: 8cad38259f8ba13bec5dc3d877fb8f411950cbedddf4dae10f2038dc7a038c92