Malicious PDF — malware analysis report

Static analysis result for SHA-256 3efc77f23c4c3808…

MALICIOUS

PDF

80.2 KB Created: 2021-09-22 20:24:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9663d9f51ef9214a00e5ca2d229935c5 SHA-1: 9a84ce3ec3909f548597b946bcda104aa20a9714 SHA-256: 3efc77f23c4c380862387956146f935f01e46b048207b81017cecfcde9c99478
176 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, embedding numerous URLs that point to compromised websites or disposable hosting, likely to distribute malware or conduct phishing. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and embedded URLs strongly suggest a lure for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://pistant.ru/uplcv?utm_term=minimum+specs+for+fortnite+mobile
    • http://hp-cnc.de/uploads/files/degono.pdf
    • http://tjjjsh.com/uploads/files/tareduzosulanux.pdf
    • http://murzilka.biz/images/uploads/file/46207539651.pdf
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/di3cc4cuoamhebcdb5fmsahucu/lujenisaxeludezogafinib.pdf
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/51193496484.pdf
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/wolatufot.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145319af1fcb---94472622435.pdf
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/25836274909.pdf
    • http://caratow.eu/userfiles/file/xokasitif.pdf
    • http://bouwbedrijfansing.nl/userfiles/file/34300332446.pdf
    • https://tasleemdubai.com/userfiles/files/18804000190.pdf
    • https://insp.biz/img/file/zuzuzijalef.pdf
    • http://ajisushionline.com/uploads/files/86444615428.pdf
    • https://pacpartner.net/images_client/imagesfile/96543716027.pdf
    • https://censcakmu.org/board/file/files/topixikamegatusefud.pdf
    • http://vvk-wiedermann.at/userfiles/file/89184351724.pdf
    • http://palestraarkadia.it/userfiles/files/kogagojosaremixipot.pdf
    • https://thietbivesinhsonhoa.com/webroot/img/files/81876145856.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe66ad3209---janorujuman.pdf
    • http://chukysovin.com/img-svc/files/jajilozale.pdf
    • http://suarezbeltran.com/aym_images/files/21057750201.pdf
    • http://remaining-mc.de/userfiles/file/gadasipifikolegovatajejo.pdf
    • http://iccjsc.com/images/uploads/files/medidutonu.pdf
    • https://clifestyle.net/uploades/userfiles/file/biletosupiv.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d749.bin
c8497f8e0f14a7b866edb2016d813cfc5cfee54a412b574cbb2ac859fc564278
pdf-font-stream PDF embedded font (sfnt) at offset 0xD749 16652 bytes
font_01_sfnt_off0001026d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1026D 16792 bytes
font_02_sfnt_off00011a84.bin
dc73b4e5b31621e4c918ed3566099e6d1836a47e1859d0f350c00d992ed17fa0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A84 10712 bytes