Malicious PDF — malware analysis report

Static analysis result for SHA-256 59c97828483f5832…

MALICIOUS

PDF

85.1 KB Created: 2021-09-12 19:13:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 913a649b5f1fd343fb63c5d966cd82f0 SHA-1: 35ca4426f98855364fe18d6580fa1e4b8219e70c SHA-256: 59c97828483f583258838c2489372f29a606b4d8e85e499d14be47666005f5c4
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files, indicating a link farm or content distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. The ML classifier and ClamAV detection confirm the malicious nature of the file, likely exploiting PDF vulnerabilities to redirect users. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://mathcountsoutreach.org/userfiles/file/35869510685.pdf In PDF document text
    • http://hzeiger.com/userfiles/file/31572254474.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/svgnpgtgu348ajggth2gpgvbct/69714672699.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/36896007060.pdfIn PDF document text
    • http://degrossier.nl/uploads/file/80776132569.pdfIn PDF document text
    • http://stluciachamber.org/uploadedImages/contentImg/file/17204863264.pdfIn PDF document text
    • https://exihomes.com/userfiles/files/nenivusokus.pdfIn PDF document text
    • http://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/58728160.pdfIn PDF document text
    • http://analhospital.net/file/files/madodupi.pdfIn PDF document text
    • https://ibeguiristain.com/userfiles/files/51016056851.pdfIn PDF document text
    • http://mimarkamilozkartal.com/userfiles/files/46645560157.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/65390314005.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/46793329652.pdfIn PDF document text
    • https://cdmsig1.com/ckfinder/userfiles/files/degotukadujuxizoguxit.pdfIn PDF document text
    • http://wwsm-us.com/files/file/86723909289.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/jutupufakolowosonawajufej.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/49155935433.pdfIn PDF document text
    • http://gfzgt.ch/upload/file/dozavowazikiwatete.pdfIn PDF document text
    • http://archetipoingegneria.it/userfiles/files/3073243775.pdfIn PDF document text
    • http://insfilings.com/skyzone_classic/upload/files/kapifiwiz.pdfIn PDF document text
    • http://xn----0tbbbfo0f.xn--p1ai/userfiles/file/27713011441.pdfIn PDF document text
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/dutozumun.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/91341188520.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=apps+like+thoptv+for+indiaPDF 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_off0000e478.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE478 19036 bytes
SHA-256: 568d833bf8a96176e25fc89148950ffb63a6d357b3bb488043f42001beb5578f
font_01_sfnt_off000115e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012df8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DF8 10736 bytes
SHA-256: 6c492e776488906486b2a5b361942bd423bc7744af9a74beba68558986f772fb