Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd86f4eb666e8ce9…

MALICIOUS

PDF

81.6 KB Created: 2021-09-24 09:11:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ad7fabb12be50853fcd6cea9d05e88ab SHA-1: 8a35dd8ff0986b11248039770069935244e4e80b SHA-256: dd86f4eb666e8ce95c65be3e46a248ec2d8774cb4ad5501e16192f82f8cf27d7
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a callback phishing lure. The document body is heavily obfuscated, but the presence of numerous external URIs, many pointing to PDF files on disposable hosting, suggests a link farm or redirection mechanism. The heuristic 'SE_CALLBACK_LURE' strongly indicates a social engineering attempt to trick the user into calling a fraudulent number.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://allytemp.ru/uplcv?utm_term=java+and+android+tutorial PDF link annotation
    • http://www.jucadent.es/ckfinder/userfiles/files/lelobibotazikowamamadaxo.pdfIn PDF document text
    • http://master-vin.ru/files/file/pijiziles.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/3758064495.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/72081598292.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/11821720350.pdfIn PDF document text
    • https://gencatakan.com/upload/file/roraxep.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/mezikozid.pdfIn PDF document text
    • http://silverk.ru/img/lib/file/62887135202.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/xedivedobakulefuvolikatun.pdfIn PDF document text
    • https://ap-qatar.com/userfiles/files/texuzise.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fitob.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109192312412294.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/75885150467.pdfIn PDF document text
    • http://mybyblos.com/userfiles/file/bofefezebelok.pdfIn PDF document text
    • https://vivaldiroberto.com/img/files/mediafiles/file/woluvamuvurenuvez.pdfIn PDF document text
    • http://tajesink.com/Uploadfiles/files/65074863140.pdfIn PDF document text
    • http://touristclub.in/userfiles/file/296707850.pdfIn PDF document text
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/panagudenozobire.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e79418b1b---tusobikuwobijujoxisejoge.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/66239608323.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mimedajuxopobuzapujumem.pdfIn PDF document text
    • http://daugiavanthienphuoc.com/media/ftp/file/kemenuxafilenikadomawu.pdfIn PDF document text
    • https://membermimpi.com/contents/files/fepowe.pdfIn PDF document text
    • http://ormansagszive.hu/upload/file/47260188486.pdfIn PDF document text
    • https://rovetco.com/userfiles/file/1609089469.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_off0000daba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D1 10096 bytes
SHA-256: df314f26649c094ac737391767185ddc93290481cd837dec44bc880cd5f58e7b
font_02_sfnt_off0001095e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1095E 18040 bytes
SHA-256: 4e9d2a23fcd72ad0a9d59613d6d2072e9a99c6e069c0ccc7a45ef2333f526bbd