Malicious PDF — malware analysis report

Static analysis result for SHA-256 957e1542b38c12e4…

MALICIOUS

PDF

67.9 KB Created: 2021-04-30 05:28:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 797060752962e3ad7d3ce7d39ba82b6f SHA-1: 89027cf693629d79f85cc2dc3b27357de77a757b SHA-256: 957e1542b38c12e40e70ca1d46cdfdfc1af33e4098667dccab42757e22bfa5a4
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites. These links are likely designed to lure users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077473d85778---zomit.pdf In PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf450adbf5---rexozuxesuzewalixujawajag.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/5a878b295d8cd2951b10207796bb6cf2/74226554314.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16080b404a9c83---71396415884.pdfIn PDF document text
    • http://aprendanow.com/wp-content/plugins/super-forms/uploads/php/files/a2b6495515e0e1b3d54c55a84ae8eab3/befomu.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/44a96199a852cbca383e870db4b05ae8/rukip.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/3da3bf4344f849cb8b81176dfb595ce0/futevevolev.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/bdd59ef25bd7ba0b2898c303cdca10a0/rudunovufajivo.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608224d944dfc---fomavadigugo.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/8e9ed5925321475546a33a9a0620cce4/xopevu.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c535c63aa1---ribixezedamu.pdfIn PDF document text
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/69aef800aa648575972fa15f5338decb/wetokodel.pdfIn PDF document text
    • https://rebel-guitars.com/wp-content/plugins/super-forms/uploads/php/files/0965eb7b65a8956720e210b432715e65/36050219504.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=extradural+hematoma+treatment+guidelinesPDF link annotation
    • https://doi.org/10.21276/iabcr.2017.3.4.18In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD66 5264 bytes
SHA-256: 6f2c998b742aecae30f3ba3f7458f611fe9e7921606cb03d5a55b02a9892c8eb
font_01_sfnt_off0000df24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF24 10404 bytes
SHA-256: 9091dec6e21963e5962e38f404576d5e27e9c79221dbc1d38052ce60a7bd15e4