Malicious PDF — malware analysis report

Static analysis result for SHA-256 53831f002d083c68…

MALICIOUS

PDF

84.8 KB Created: 2021-10-07 08:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 7d90afc74808ca9cb9e1fac58b11a2c2 SHA-1: 62f9391818552bab29497bae7edbc74912e80721 SHA-256: 53831f002d083c68e6fb12310b401f05d6d9f43a0bdaa14c10819b9f45c37ff4
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to domains identified as disposable hosting or compromised CMS uploads, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://thestarbusan.com/FileData/ckfinder/files/20210913_021B599312A23E0F.pdf In PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/b0t033hsgg29o9iv02d5b3ia5i/67815587568.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/rigelomiboximamuvirefeg.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210904055424.pdfIn PDF document text
    • http://indianspringhomes.com/userfiles/files/wipovuvigevazojuni.pdfIn PDF document text
    • http://chongqinghaohong.com/upload/files/xetuzimonir.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/161529dc594890---58311290362.pdfIn PDF document text
    • http://euroambulans.pl/userfiles/file/85671328311.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/90080982858.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/71974346104.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/gowamupiwubokazevewonaji.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210910_C4091BD17B5AAD0C.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614206b36299c---xonabizojimid.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/salimewinufapud.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/90903854388.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/dotajojafugoguxenawubo.pdfIn PDF document text
    • http://fygl.net/uploads/file/090145322391.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/fibixaligovipiwetufowis.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/nelakabo.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/wozaritifewaxojulizu.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7497bcbf3d1bcfa2ad6f085dc115d874/24392781714.pdfIn PDF document text
    • http://kriosispl.com/cote_dor_import/admin/ckfinder/userfiles/files/74513991933.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.com/userfiles/file/faniwubavedi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=house+of+night+otherworld+loved+pdfPDF 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_off0000e4a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A5 18480 bytes
SHA-256: 7c365ae368a74b917570b3b46b29e01cb122aeb1e2e73601c0df8cd05dd47ae1
font_01_sfnt_off00011471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11471 10856 bytes
SHA-256: fa18bc31e01ce0a07e434944ceec610ea6b40b7824ba7f4d05acfd9065d55cac
font_02_sfnt_off00012d46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1