Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f71e5105ac0186c…

MALICIOUS

PDF

79.6 KB Created: 2021-07-27 19:13:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: c7702c0139573432291f2ecbbdd40437 SHA-1: 8ff21bcc2b38bd783d770241d22f4d0c76de655e SHA-256: 1f71e5105ac0186ce46c2642b1eea79bade10a5dc403df1eebf0c95507b316ba
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, with heuristics indicating it functions as a link farm. Multiple URLs point to compromised CMS upload directories and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and unreadable, providing no further context on its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/2b520c86edc1535cb50420137d346bc6/73078269008.pdf In PDF document text
    • http://businessvaluationapp.com//fck_files/file/pukiwefatovepoxaxom.pdfIn PDF document text
    • https://altbuket.ru/files/77659737835.pdfIn PDF document text
    • http://azizolace.cz/images/file/68069801674.pdfIn PDF document text
    • http://agisma.ru/files/pages/files/vebijejegog.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/femepivotirisu.pdfIn PDF document text
    • http://citywideok.com/clients/75789/File/47732309227.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tunavawimugumeguzorunud.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/90448619473.pdfIn PDF document text
    • https://nestaerospace.com/uploads/file/47030032692.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4e8c7f830---zovesadenuvix.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/56759214442.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/4od7ornk95kv8qsufeqi2m32c3/xaxubokawefu.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080fb2f9c0c2---niniko.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/14945880342.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ae6ec3cc61b---lituzime.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/ad400ed1d75c4a3c90cd301dc0f209f9/xosiduparolexukida.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/libosa.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/dasesopopotinatim.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fb1f6981a70---53279531696.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/56ab1277e7895a2847215f6180f597d5/zetizozotemenetefep.pdfIn PDF document text
    • https://lanhcongnghiepthinhphat.com/upload/files/mubavesodesorukovodoragok.pdfIn PDF document text
    • https://fcksa.com/ckfinder/userfiles/files/13735817134.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=sc+dmv+appointments+onlinePDF 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_off0000d4b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B6 16668 bytes
SHA-256: 619d843590f7f780335cadfd0ea61c248b8c280f0ccf88b73061488560882568
font_01_sfnt_off00010036.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10036 10716 bytes
SHA-256: 298236b9376f9501744ee1e4a3c74d7a90c3dcf534808e1df4a7218e8d838c9e
font_02_sfnt_off000118d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1