Malicious PDF — malware analysis report

Static analysis result for SHA-256 33d76df2dba7b910…

MALICIOUS

PDF

80.0 KB Created: 2021-07-13 19:51:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e1341c76b74f19f485db8b6a880887ab SHA-1: d30d55b0390f46a900518264f47429204114ab84 SHA-256: 33d76df2dba7b910faabb3a47945f53c0b4bcafeba8183e527aa732eafc9c86b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was identified as malicious by multiple heuristics and an ML classifier, with ClamAV detecting it as a phishing trojan. The file functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, likely intended to lure users into downloading further malicious content or visiting phishing pages. No scripts were extracted, but the structure and URL distribution strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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
  • 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://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3394b11d2---62640073123.pdf
    • http://tcurryproperties.com/konadnew/userfiles/file/malifisuvibifuvom.pdf
    • http://hanboo.cn/Uploads/file/2021062303591470554.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3686ce6d59---feparoju.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7305c6c10---13525206481.pdf
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/a728c6bd02e1a6311005c57e46d128da/fedopat.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c27d741077b---zavubodopiguvigelelune.pdf
    • http://hcvitamin.com/webroot/img/files/13118868856.pdf
    • https://emilline.dk/ckfinder/userfiles/files/1276075025.pdf
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16082bd57232ad---85318182300.pdf
    • https://serka.com/serka/upload/files/nuranagepew.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160e9061b5ffd8---migoxumafafekelume.pdf
    • http://assytekservizi.com/userfiles/files/44971927105.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/3704a64c4bbb0f8cdf7b53c1d6e35035/mobekemasudemubuguw.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c54186359---92661857998.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/696211a7c17bbed5374feb0ddd39c09e/bipaxi.pdf
    • http://goodwynva.com/clients/d/de/de91e19d235d8a3764238851c6b73f99/File/56149181619.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=1+year+old+boy+head+circumference
    • 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_off0000d36d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD36D 16792 bytes
font_01_sfnt_off0000eb84.bin
c437ecc87a8ea770f68311983970cf9bf83ed92df67328b1b214d4535bbd01ef
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB84 10784 bytes
font_02_sfnt_off0001041b.bin
7624a852301b63e7b2a9439014bf24e689549b2e0e7b6da216a3ea83a250519b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1041B 18028 bytes