Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3c6d3976fdc5870…

MALICIOUS

PDF

80.1 KB Created: 2021-09-24 02:59:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7df5d9a82a766d7776b7c80cfb7909bf SHA-1: 453357d5188e90d0bcd4e27a7266543a4403db03 SHA-256: e3c6d3976fdc587030ae2bf279ceb3d6c88aa1d5f20011664bdecf64f931fa10
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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 http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/78831285911.pdf
    • https://navliecky.net/userfiles/file/dimorarinovozefo.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613058fbe3019---zepub.pdf
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/lufusurod.pdf
    • http://kastely-vacduka.hu/fileok/file/1275133391.pdf
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148e46faaf22---puripiri.pdf
    • https://vanvoorst.info/uploaded/file/1334031091.pdf
    • http://cuanhomkinhtoanthang.com/media/file/dizimawel.pdf
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/89eb6b39f62008d3fb17300388beaade/mozunoxopiriju.pdf
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/kexorabesumizep.pdf
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/69021005352.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133a957a54e6---lizutad.pdf
    • http://canoeing.by/pics/files/89188161020.pdf
    • https://drosamahetta.com/userfiles/file/31806038631.pdf
    • https://saikekanglun.com/filespath/files/20210917010230.pdf
    • http://techsystem.gr/data/uploads/ckeditor/files/baxojitopananozimagab.pdf
    • http://jysfh.com/upload_fck/file/2021-9-10/20210910204512398320.pdf
    • http://knipia.com/userfiles/file/kuxarapidu.pdf
    • http://hwangtosidae.com/userData/ebizro_board/file/fifegenagipiwadawowixog.pdf
    • http://vetportonaccio.it/userfiles/files/rejobarobunujagiz.pdf
    • http://dhleisure.com/ckupload/files/97863292426.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=antutu+benchmark+apk+download
    • 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_off0000d433.bin
89a388bab4cab77b34a8b004baafedff68de4b1ad23bfd17a5e3406546f3108e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD433 10916 bytes
font_01_sfnt_off0000ed22.bin
b8ad1764856878e02e49358069312ad5b2744b32fec0964204c5c24cf90b5d48
pdf-font-stream PDF embedded font (sfnt) at offset 0xED22 17612 bytes
font_02_sfnt_off00011b12.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B12 16792 bytes