Malicious PDF — malware analysis report

Static analysis result for SHA-256 77bf775eb8c36478…

MALICIOUS

PDF

78.0 KB Created: 2021-09-23 12:09:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 151041da49135fa583fd04d2f2c75eae SHA-1: 4da30934db0252c12c138ca2ca32995ec64c81de SHA-256: 77bf775eb8c364788b8d3caa27c7f65fb4f597d579f39c7850bb3ffd785a18ca
146 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with a high heuristic indicating it functions as a link farm on disposable hosting. The presence of ClamAV detection and ML classification strongly suggests malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with exploitation attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://archism.ru/uplcv?utm_term=signos+y+simbolos+guia+ilustrada+de+su+origen+y+significado+pdf PDF link annotation
    • http://yugang360.com/upload_fck/file/2021-9-19/20210919215916868575.pdfIn PDF document text
    • http://bagliodeimille.it/userfiles/files/90139052673.pdfIn PDF document text
    • https://cmflower-kkc.com/ckfinder/userfiles/files/vefubejajoxa.pdfIn PDF document text
    • https://uleshuzataruhaz.hu/files/file/sekatu.pdfIn PDF document text
    • http://yuanda-boiler.com/d/files/fobodod.pdfIn PDF document text
    • http://b40555.handyfriendship.com/upload/files/kusemetevagalobuxem.pdfIn PDF document text
    • http://mobilahomedesign.com/userfiles/files/72253455427.pdfIn PDF document text
    • https://luckyfood.itweald.com/uploads/files/6143d3d33e034.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/77624156987.pdfIn PDF document text
    • http://evpltravel.com/xv_image/file/gojapufefivabilaxomej.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/vediroso.pdfIn PDF document text
    • http://ohsongpharm.com/ckfinder/userfiles/files/94370843066.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/xejukokeferu.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16138eabc3a48b---jasiguraroziriwa.pdfIn PDF document text
    • http://dpholding.ru/uploads/files/55288291854.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/bezusoriwofutezakatenoxu.pdfIn PDF document text
    • https://thailonghoang.vn/upload/files/34641818962.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/xexirirefipota.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/lamojopogebonano.pdfIn PDF document text
    • http://quranday.org/userfiles/file/91654831513.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/mawirifamunalu.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210920184638.pdfIn PDF document text
    • https://mcdelandes.ca/uploads/file/14750401058.pdfIn PDF document text
    • https://lapdonline.org/file/78474195401.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_off0000c4d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dceb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEB 19212 bytes
SHA-256: 3d3c12a1e14325c1c384770cd66d8399f2bc408f0a3a48b2e91f30b7f88214c4
font_02_sfnt_off00010d78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D78 11392 bytes
SHA-256: e137b87f6f50f1d98a536f966ec5e76348d33d803b3bcbfec1cbb96ee6c33d17