Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4dd67868d3865b5…

MALICIOUS

PDF

77.3 KB Created: 2021-06-26 10:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cb218299182307ebfc54191b9a0392d2 SHA-1: 42f95be3daad446cac790d66aa24f3fce7d61800 SHA-256: b4dd67868d3865b5a8c168bda889d5fd2e4ea41b2177d0e196f4f2c8d2e80095
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to lure users to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608cd3f29d652---morebabomenutuko.pdf
    • http://gymostrov.org/gymostrov/userfiles/file/buxifixaruxufokodatufopi.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/0aa820fc4d8ad58b5c65dbaeff3e8f03/65195790039.pdf
    • https://hometeamcorp.com/images/usr/bagukodixujuneribe.pdf
    • http://nuocmambason.com/upload/fckimagesfile/cd61b7a846627a6c1fe577590ee19394.pdf
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/jg3akl2p5tempk8qg3gkp1gour/zibagetofi.pdf
    • http://consol.hu/images/uploadedimages/file/wozukunodiwagupusade.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a565bc249f9.pdf
    • http://aimic.com/userfiles/file/jetaveponibogex.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b10d1823cec---sirezigawofaresituxa.pdf
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/8a3550cfef606d999d53e4a3a368c7df/widawono.pdf
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609191b5d8d28---joloborebeganizamafelene.pdf
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/d3jhod6m9d61muqaqjnlo4cc7h/jujulelapamemim.pdf
    • http://thamdinhgiadaiquang.com/img/files/4188501480.pdf
    • http://internationalnetworksolutions.net/files/
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0619455d57---79937028342.pdf
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/1753add2ef7f77c0ae90ee73c5aa5daa/dutawonoxifobonikijenoxot.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/4lv1dhj33u7532lrs4i7fq6vni/93272883268.pdf
    • http://dakmet.pl/upload/sarezakedawupotexepelavi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=national+residence+hall+honorary
    • 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_off0000cc43.bin
f5e16669c7b0013a47206d652e99fb7fd58dcd103084dc999e1df23aed578666
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC43 16716 bytes
font_01_sfnt_off0000f828.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF828 16792 bytes
font_02_sfnt_off0001103f.bin
a062bed3eafd900726587f6a3656162d26d0227ded039fbf87897285ec63d195
pdf-font-stream PDF embedded font (sfnt) at offset 0x1103F 10560 bytes