Malicious PDF — malware analysis report

Static analysis result for SHA-256 42af673b1f4fc8d2…

MALICIOUS

PDF

98.1 KB Created: 2021-08-29 02:47:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2dd0adde402c51240209bb4ac31ddc4b SHA-1: a7cecafe96bb20fba2e7eabda20ec564825b620e SHA-256: 42af673b1f4fc8d294b5f44e61e0d6d57d4d597842fb42f94ee4d4f25932ceba
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://anjingliar2.com/contents/files/98371032244.pdf
    • http://folientastaturen.pl/_data/file/robig.pdf
    • https://turismopontevedra.com/ckfinder/userfiles/files/nodozu.pdf
    • http://yi-xiang-yuan.com/CKEdit/upload/files/zezabesikulevolatexixuzos.pdf
    • https://nestaerospace.com/uploads/file/pokufufimuse.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/4702e49bb8dadf38802015869b8b342e/tisekuribemasok.pdf
    • http://jca-t.com/fck_image/file/jelijezekomudu.pdf
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160799f51d5bea---81255735389.pdf
    • http://yesilderecine.com/admin/editor_resim/file/56148798257.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1608285660441f---45904273188.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0e42dc4875---bujebowoji.pdf
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/0b01b5b0667314a74621c7e8db9f7e05/79025661946.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b18e2de262d---doxugiloridif.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/22563871170.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805650ad825---gigofomaza.pdf
    • http://jtylek.pl/Upload/file/10203326509.pdf
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16077f63910a7b---31553332903.pdf
    • http://kashima.cc/userfiles/file/xonagana.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610c537e7814c---47482626584.pdf
    • http://megat.pl/uploaded/fck_files/file/kelojatinejolixim.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/80d42b986c9522838a92a9533b85ccd2/98515641754.pdf
    • https://sanruouvang.net/images/uploaded/file/remopez.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16123409e21714---24834094558.pdf
    • http://extintoresorigen.com/images/editor/pelef.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/f78220d0b14c316edd82427708500d0e/ziwubisavajepasesodunu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=wh+question+hierarchy
    • 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_off0001188a.bin
f65bd0b2b989788b56d41cc908f0db750f27d592b8631dadcd8c33d50276ee73
pdf-font-stream PDF embedded font (sfnt) at offset 0x1188A 10636 bytes
font_01_sfnt_off000130ea.bin
0d4bd12abfa8a27f88b89664c5fe6fa0611c5562aaa57215a7572aadfdb6deae
pdf-font-stream PDF embedded font (sfnt) at offset 0x130EA 18944 bytes
font_02_sfnt_off0001616e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1616E 16792 bytes