Malicious PDF — malware analysis report

Static analysis result for SHA-256 20aca897a2d82dec…

MALICIOUS

PDF

75.6 KB Created: 2021-09-12 07:17:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 18704e9fa71cd23200890f2306c1c9f0 SHA-1: 09f0c2b57d3ec6a49f069477e7dd22ba6932a677 SHA-256: 20aca897a2d82dec55cfed68e22107e48a3d2c4abc94631464335dc50959eab3
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm and employs a callback lure, suggesting a tech-support scam or phishing attempt. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious sites or engage them in a fraudulent phone-based interaction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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.
  • 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 http://instant-image.net/UserFiles/Site/File/vonitudadoloxabix.pdf
    • https://srmhomes.com/images/bulk_images/files/damikitanogoxododo.pdf
    • https://lazdynumokykla.lt/userfiles/file/29485039169.pdf
    • http://etoprosto.ru/ckfinder/userfiles/files/96272510521.pdf
    • http://www.puhito.hu/uploads/wefovubikofevo.pdf
    • http://futimisdev.com/userfiles/file/45848793668.pdf
    • http://topbuild.net/content/xuploadimages/file/31959407542.pdf
    • https://burlingame.com/wysiwygfiles/file/tajifeforilerorilolekiwuw.pdf
    • http://majorpropertygroup.com/userfiles/files/59855631533.pdf
    • http://studionegro.net/userfiles/files/wodosetapideduwad.pdf
    • http://immobilieninvestors.de/userfiles/file/53480810300.pdf
    • http://ifa-astrologie.de/userfiles/file/89344463717.pdf
    • http://sz-nuoyi.com/Upload/file/2021090411135624060.pdf
    • https://sbsoftware.ro/admin/userfiles/file/xosunigikawede.pdf
    • https://rijst.nu/userfiles/file/9274432788.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f25071fcd---72109318252.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/8675945984fa2b2d40ea372112ce948b/tonis.pdf
    • http://gyogytornasz.hu/editor_up/wedebaretopixebupop.pdf
    • http://sdv.sk/userfiles/articles/file/89880845045.pdf
    • http://www.hon-ro.hu/userfiles/files/vizevadujamawogovi.pdf
    • http://chiari-web.com/ckfinder/optimist/files/numerawilubivusa.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/1646143c4d7d3eb2844647efe107eb41/26507833229.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=apk+android+1
    • 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_off0000c5b2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B2 16792 bytes
font_01_sfnt_off0000ddc4.bin
76049bcf831f688c3f54d2a4cb7eb8065737682430b1fcb2240a64dac6447b22
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC4 17604 bytes
font_02_sfnt_off00010b23.bin
5cfddf039a5ab6965604602c33fe2d7647195ae777bd8378e2ca404633b0eff4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B23 10068 bytes